Update the null check in GameEngine.
Copy editing.
Fix compiler error in GameEngine
Log the value of APP_HOME on startup.

The scripts generated by the application plugin, set APP_HOME to the root
directory of the app, such that $APP_HOME/bin/, $APP_HOME/lib, and such work as
expected.
Simply logging platform data on startup.
Implement having date and/or time in log statements.

Previously the date included the time. Now there is both a DisplayTime field
for the time and DisplayDate doesn't include the time ;).
Drop TODO file in favour of Evernote.
Utils.getUserDir() now uses memorization.
Pull Utils.Xdg out to it's own rewritten class.
Change Xdg to use static initializers and sanity.
Document Xdg class.
Use Xdg in GameEngine logging, instead of System.getenv().
Add .cmd/idemo.cmd.
Fix up pretty print of Xdg stuff.
Specify more var's to :demos:*:pc:run
Fix up some .cmd scripts.
Added .cmd/irdemo.cmd
Unify direction of slashes in gradle/runDemo.gradle.
Fix using rootDir where projectDir was needed.
PcConfiguration now uses Xdg instead of Monkey Business.