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)
Fixes broken link for MockSmtp
Updates version of LaunchBar
Fixes broken hash for SweetHome
Merge pull request #649 from shostakovich/fixes_for_broken_casks

Fixes for broken casks
Merge pull request #648 from webgefrickel/key-remap-4-mac-book

Add KeyRemap4MacBook in version 8.3.0