This fixes https://bugs.launchpad.net/mixxx/+bug/1804411.

Conflicts:
	src/library/searchqueryparser.cpp

so that shorter time formats (i.e. without fractional seconds) don't take up to much space.

This was previously guarded by an #ifdef Q_WS_X11, but switching
to Q_OS_LINUX caused a link error:

/usr/bin/ld: lin64_build/mixxx.o: in function `MixxxMainWindow::MixxxMainWindow(QApplication*, CmdlineArgs const&)':
/home/uk/Projects/Mixxx/mixxx/src/mixxx.cpp:187: undefined reference to `qt_x11_wait_for_window_manager(QWidget*)'

It turns out that Q_WS_X11 is no longer defined with Qt5, yet it
does not seem that building Mixxx without the call to
qt_x11_wait_for_window_manager has caused any issues, so I presume
it is safe to remove it now. This was the only place in Mixxx
where Q_WS_X11 was referenced.

Tango :: some improvements

let Key widget display key, cents or both (or nothing)

hack around Xlib deadlock

… DE translation, nearly 100% translated.

* At least on macOS, the incomplete translation was auto-selected, if the systems locale is DE.
* Both translations share the same name in Mixxx Preferences > User Interface > Locale > German (Germany). Correct would be for DE = Deutsch, and for DE-DE = Deutsch (Deutschland)
 This issue is also with other translations, e.g. PT and PT-PT

Changed terminology (also in the Transifex DE-glossary):
  * Artist = Künstler (was Interpret)
  * Track = Track (was Titel).
    Track is established in daily language use. This fixes some curious situations we had before, e.g. for source strings like "Track Title".

Also fixes several whitespace, punctuation, and consistency errors in the target language.

We should not call numbers here (was "4 or 8"), the description needs to be generic enough if a skin decided to show a different # of cues. We support 36 (afaik).
Also the control does not affect the # of hotcues displayed in the waveforms.

Current skins do need no update, since they display the number of hotcues they display in the controls label.

The headphone volume buttons control the hardware volume of the
headphone output. They should not be mapped to Mixxx's software
gain control. Also, mapping buttons to a knob is incorrect.
Reported by a user on the forum:
https://mixxx.org/forums/viewtopic.php?f=3&t=12340

...to remove Qt4 dependencies when building on Fedora!

lp1783392: Configurable debouncing timeout for WSearchLineEdit

Remove redundant search call

…_safety

WSearchLineEdit: Handle invalid debouncing timeout

Update DE (German) language

QCollator: Extensions and minor improvements

qt5keychain ist not available in Ubuntu 14.04 used by Travis CI.

This reverts commit 38dc3f4.

Use QCollator for sort library.

Fix QtKeychain incompatibility between Debian/Ubuntu and Fedora

…08222

Eject crash fix

Conflicts:
	src/engine/enginebuffer.cpp

Conflicts:
	build/debian/control
	build/depends.py
	res/skins/Tango/loop_jump_controls_left.xml
	res/skins/Tango/loop_jump_controls_right.xml
	src/engine/enginebuffer.cpp
	src/preferences/broadcastprofile.cpp
	src/preferences/dialog/dlgpreflibrary.cpp

``lupdate src -recursive -noobsolete -extensions cpp,h,ui -ts res/translations/mixxx.ts``
Scanning directory 'src'...
Updating 'res/translations/mixxx.ts'...
Found 2392 source text(s) (3 new and 2389 already existing)
Removed 1 obsolete entries

Hercules DJ Control Instinct: unmap headphone volume buttons

``./wxl2pot.py -l Language mixxx_en-us.wxl po/mixxx.pot`

`tx pull -a -f --parallel --minimum-perc 1``

In ZSH:
``for i in po/*.po; do destfile=${i#po/}; ./po2wxl.py -l Language -f -p 1 $i mixxx_${destfile%.po}.wxl; done`

In ZSH:
``for XX in res/translations/mixxx_*.ts; do lrelease -nounfinished $XX -qm res/translations/${$(basename $XX)%.*}.qm; done`

This is a mapping for the Numark Mixtrack Platinum. Most features of
the controller are supported including the LCD screens and 4 deck
control. This mapping is targeted for Mixxx 2.0.0.

Notes:
- FX buttons always operat channels 1 and 2. This is a limitation of
the controller that could be scripted around, but I got lazy (also how
it works in Serato).
- Both FX dry/wet strips control the same effects chain and will affect
both channels 1 and 2 if effects are enabled on them. Serato has
isolated effects banks for each channel.
- The "BEATS" knobs are not mapped, this concept did not translate
cleanly to Mixxx.
- Sometimes there are artifacts in the auto after long spinback
maneuvers. This may not have anything to do with the controller.
- The sub-beat auto-loop buttons do not light up when enabled unless
the shift key is pressed. This is different from how the work in Serato.
- Master sync enable and disable works like in the Mixxx software interface,
not how it works in Serato. Shift-sync is not mapped.
- The slip mode indicator is not mapped, this is trivial to fix (midi
codes are documented in the JS file), but I couldn't figure out how to
use slip mode in the Mixxx interface.
- The up/down indicators on the LCD screens to indicate which direction
to adjust the pitch slider are not implemented. It's possible to do, but
would require some scripting.
- Browse knob press is unmapped. I couldn't get this to do something
sensible in Mixxx 2.0.0. Version 2.1.0 seems to have more sensible
options.

…jog wheel position

Behave differently when the platter is spinning forward vs backwards
but not being touched. Effectively this changes causes the track to
stop scratch mode and start playing sooner when moving foward vs
backwards. This allows better spinbacks, and more natural cueuing when
seeking backwards with the platter and for cleaner exits when
scratching when pushing the platter forward at the end of a scratch.

Thanks JosepMa for this suggestion.