Move xconfig files to Xconfig group

Currently xconfig files were cocoapods related
Add Project.xcconfig

Will contain project wide settings.
Fix typo: Xconfig => Xcconfig
Remove Podfile.lock from ignored files
Add Podfile.lock
Add Project and App-Common xcconfig files
Update Podfile.lock
Start using @import statement
Add basic project settings to Project.xcconfig
Add preliminary warning settings to Project.xcconfig
Inhibit all warnings from Pods

A bit iffy choice but there's not much that could be
done to those.
update Project.xcconfig