Update to new CLIntegracon Patch

[CHANGELOG] Add changlog entry for sanitization of special characters in build configs in target environment header

CHANGELOG entry for https://github.com/CocoaPods/CocoaPods/pull/2532.

Spec for changes introduced in https://github.com/CocoaPods/CocoaPods/pull/2532

Configuration specific preprocessor definition can generate a lot of warning

Use a var instead, as per @alloy

Especially warn a user in the case of a RC version.

Addresses a regression introduced in https://github.com/CocoaPods/CocoaPods/pull/2601

[TargetIntegrator] Ensures that the user project is not saved when there are no user targets integrated.

[Resolver] Added tests, notice if the required version exists in multiple sources (CocoaPods/CocoaPods#2556)

Fixes https://github.com/CocoaPods/CocoaPods/issues/2591

[TargetIntegrator] Ensures that the user project is not saved when there are no user targets integrated.

[TargetIntegrator] Ensures that the user project is not saved when there are no user targets integrated.

Remove references to Source#data_provider

Closes https://github.com/CocoaPods/CocoaPods/issues/2586.

[Downloader] ensure that a downloader failure results in a DownloaderError so the Downloader can catch it

Helpful for https://github.com/CocoaPods/cocoapods-downloader/pull/36

Modify add_xcode_base_configuration to respect existing base configurations

Thanks @alloy!

Clarify why .git/ is removed from comparison

We have only so much time in a day, it’s time to take stronger stances on support.

configurations:
 - Do not change the base configuration when it is already set
 - Notify the user when there is an existing base configuration

Change string quoting from double to single quotes.

Split lines longer than 80 characters into multiple lines.

Quote initial string fragment with single quotes rather than double quotes.

[UserProjectIntegrator] Allows the use of the `GCC_PREPROCESSOR_DEFINITION` flag `${inherited}`  without emitting a warning

Closes https://github.com/CocoaPods/CocoaPods/issues/2577

[Outdated] Refine pod outdated to show what pod update would do