Add KeyRemap4MacBook in version 8.3.0

A very nice and free tool for custom keyboard-mappings
Use install instead of link / pkg file in dmg
rename of the file/class to match conventions

no dashes in filename and uppercase in class-name (no camelcase)
Merge pull request #648 from webgefrickel/key-remap-4-mac-book

Add KeyRemap4MacBook in version 8.3.0