Improve verbosity of audio errors

GPU/CiTrace: Avoid calling GetTextures() when not necessary.

Kernel/Events: Log an error when trying to create Pulse events and timers

APT/Applets: Renamed the members of the SignalType enum.

Minor formatting change

Related to #1904

Names now make sense and match 3dbrew.

Fix mingw compilation support

Support additional screen layouts.

And other minor style changes

Fix Travis build issue on mac

Minor Menu Fixes

Also minor style changes

Make small screen stay at 1x, and large screen maintain its aspect ratio.

Allows users to choose a single screen layout or a large screen layout.
Adds a configuration option to change the prominent screen.

AC_U: Stub functions, used if EULA agreed

Update Donation Info in Readme

Link main site donation page in readme instead of providing further donation info there.

NWM: stub Initialize with an error

Update CONTRIBUTING.md

Fix build on DragonFly and FreeBSD

Small fix to let IDA see target.xml

Citra SDL2 doesn't have a launcher, and citra.desktop tries to execute
citra-qt which is N/A unless built with ENABLE_QT. Limiting installed
files to one of the options also makes it easier to split them into
separate non-conflicting packages downstream.