Revert "Install libpitch using CocoaPods"

CocoaPods is nice, but I'm not a huge fan of how it packages libraries
(specifically, how it statically links them), and it was easy enough to
build Squash before anyway.

This reverts commit ea1fa253ffd68542ce0077274b6c954a501eb78b.

Conflicts:
	.gitignore
Merge branch 'master' into plugins

Conflicts:
	Squash.xcodeproj/project.pbxproj