Remove trailing whitespaces in .h, .cpp, .c and .lua files.
Merge pull request #237 from mounirlamouri/trailing_whitespaces

Remove trailing whitespaces in .h, .cpp, .c and .lua files.
Various cleanups in some C++ files.
Merge pull request #234 from mounirlamouri/cpp_cleanup
Add a script to check whether files in the working directory have trailing whitespaces.
Add a rule in Travis to check for trailing whitespaces.
Merge pull request #238 from mounirlamouri/travis_trailing
Fix encoding of comments.

This makes some files use utf-8 and fixes a weird quote in another comment.
Update gitignore to catch more cmake cruft.
Merge whitespace commit into sdl2 branch.

This merges commit 4cd937909b and throws away all the changes, since we've
already done the same work in the sdl2 branch.
Merge branch 'master' into sdl2

Bring sdl2 up to speed with latest master changes.
Fix Mac build w/o freetype.
Merge branch 'mac-no-freetype-fix' into sdl2