Configure as extension only for app extensions

Set the APPLICATION_EXTENSION_API_ONLY build setting if integrating with
an app extension target

[IntegrationSpecs] Update for the evaluation of podspecs in the own directory with the podspec option

[PodspecSource] Evaluate :podspec dependencies in their own directory if the path is local.

[Analyzer] Only update git sourced spec repos

[ErrorReport] Show full command in the error report

[Podfile] Change the default spec repository to the master

Closes #2946

This reverts commit 1eb3584a.

Fix for issue #3008 Swift Pod causes runtime failure in Obj-C host app o...

prepended $(inherited) to OTHER_LDFLAGS and HEADER_SEARCH_PATHS to the generated xcconfig

Closes https://github.com/CocoaPods/CocoaPods/issues/3038.

Fix uninitialized constant Class::YAML crash

[CopyResourcesScript] Copy only the resources required for the current build configuration.