Add static analysis features to Kin

[Serchinastico]

There are a lot of problems in pbxproj files and most of them are always the same!
We could handle the most common ones with Kin by using the parser ANTLR creates for us.

Some of the issues we could deal with are:

• NULL references [Remove them]
• Unknown UUIDs referenced from groups [Remove them]
• UUIDs of files that don't appear in any group [Remove them]
• Duplicated UUIDs [Ask the user which one should we pick or try merging them]

We can create separated issues in github when we start developing them.

[pedrovgs]

Just for the last point. Is this tool useful for picking different UUIDs when they are duplicated?

[Serchinastico]

After reading the documentation of mergepbx a couple times I think it's pretty much what we are looking for but I think we won't be able to use it, the project has a very basic grammar to describe pbxproj files (dictionaries and such) while Kin knows a lot more of the format (names of each field, order and so). We can take some ideas from it though so yeah, good catch!