Remove OS-specific entries from .gitignore.

.gitignore should only store items that are generated by the code in the
repository. If your operating systems generates temporary files, put
those in your .gitignore_global.
Mv etc -> share, use applicationDirPath (fixes #30)

Also build outside of bin.
Add DATADIR, search_paths for game_data.ini
Add .travis.yml
Compute checksum internally without calling md5sum
Merge branch 'checksum' into DF2014
Merge branch 'gitignore' into DF2014
Merge branch 'pidof' into DF2014
Merge branch 'share' into DF2014

Conflicts:
	.gitignore