[gemspec] Bump Xcodeproj to `~> 0.21.0`
[Rakefile] Ensure hg is installed before rebuilding the integration fixtures

Closes https://github.com/CocoaPods/CocoaPods/issues/2977
[gemspec] Bump claide to `~> 0.8.0`
[gemspec] Bump molinillo to `~> 0.2.0`
Add support for swift source files
[Doc] Add group for better separation
[Doc] Add some method-inline comments
[Spec][Fixtures] Add a Swift podspec fixture

Never compare that to banana-lib!
Add methods to check if a target uses swift
Support framework as type for generated target
Integrate product_refs of generated frameworks
Migrate from static library to framework
Set headers as public if needed in PodTargetInstaller
Generate an Info.plist for frameworks
Add Swift specific settings to the generated xcconfig files if required
[Spec] Change label of target definition in spec for AggregateTarget

Choose a label for the target definition which contains whitespaces.
Add target type specific settings to XCConfigs
[Refactor] Extracted product_basename from Target's product name getters
Add helper method Target#c99ext_identifier
Ensure that the PRODUCT_NAME is a C99ext identifier