Add application category for OS X

Because OS X apps generally don't like apps being subfoldered (updates miss their targets), as of Lion the Finder has had an Applications-specific View by Application Category view. It sorts by a piece of metadata called LSApplicationCategoryType which if missing, dumps the application in the "Others" section at the bottom. This commit adds the correct application category for FontForge, "Graphics & Design".
Merge pull request #1350 from duanemoody/master

Add application category for OS X
README Updates

1. Wrap long lines to 80 chars.
2. travis.yml -> .travis.yml in README.
Merge pull request #1298 from kartikm/README-and-travis

README Updates