Incorporate Minor Fixes

This is a stable maintenance release that fixes minor issues. Note this code is DRAMATICALLY more reliable at reboot than the original code. Pay close attention to the readme information. There is no need to use an SD card with this release, instead much faster and more reliable mSATA device is the way to go. Some performance measurements are provided for those wondering how different brands perform.

Reboot Performance Improvements

Perhaps the most important fixes to pidesktop yet. The reboot timing issue has been solved using gpio features from the latest Pi 3B and 3B+ firmware. This allows rapid reboot processing. A BLANK SD card is still recommended, but boot from USB works very well in all cases now.

Split reboot service processing

Split reboot (#11)

* better comments in services

* Update pidesktop-powerkey.service

* Update pidesktop-shutdown.service

* Create pidesktop-reboot.service

* Update pidesktop-reboot.service

* Update pidesktop-shutdown.service

* Update postinst

add reboot service

* Update postrm

add reboot service

* Create pd-reboot.py

new reboot service file

* split out reboot service

Tested with 3 Model B+

Updated RTC support in shutdown service.

Reimagined Pi Desktop Case support software

Rewrote and documented systemd services, renamed many of the utilities and other files. Installation instructions for building a system that boots from USB mSATA SSD with a simpler installation process. Note that the boot from SD card instructions have not been updated, but the utilities are provided but renamed.

Note there are a few improvements aside from general cleanup:

• The RTC maintenance commands in systemd are unneeded, they are part of the OS
• The powerkey service causes the case LED to blink once - nice to know it is there
• The shutdown service understands if it is running because of power key initiated shutdown