Merge the translations into the desktop file on install. Closes #1109.
Add stuff to .gitignore
Add dependency on libaegisub for the tools directory
Add configure check to verify that boost was built with ICU support
Add an option to skip all of the slow configure checks

Cuts the total runtime of the configure script from 19 seconds to 5
seconds for me.
Merge remote-tracking branch 'upstream/master'