Diaphora 3.1

This is a bug fix release. It fixes the following issues since the previous version:

BUG: It seems that the directory name "database" might conflict with an IDA supplied module also called database.py
BUG: The WHERE clause for the Microcode SPP heuristic was wrong.
BUG: Do not crash in patch diffing sessions if there is no pseudo-code available.
GUI: BUG: The main UI dialog might not be 100% visible with some screen resolutions.
GUI: BUG: Adding manual matches was partially wrong.
GUI: BUG: After closing the "Interesting matches" tab there was no way to show it again (like F3 does with other choosers).
WORKAROUND: Fix for issue #263. It seems IDA might crash if the decompiler is not available and Diaphora tries to use it.