Fix library path and cleanup

[hirschfl]

This pull request contains three changes:

• Updated gitignore to ignore Xcode specific files like ".xccheckout"
• Updated path of "libiRockey301_ccid.a" from a hardcoded path to a relative path
• Removed the missing "call_lib_Prefix.pch" from the project file

The updated path change makes it possible to build it on a third party computer.