[Gemspec] Bump Xcodeproj
[Resolver] Gracefully terminate if unable to find a set
[Installer] Call per install hooks before cleaning
[Acknowledgements] Don't crash if the license file doesn't exists.

Closes #828
[Analyzer] Adapt for TargetDefinition#link_with_first_target
[Specs] Fix resolver test
[Gemfile] Point to repos instead of to gems