Allow EXPANDED_CODE_SIGN_IDENTITY to be unset

This is unset for some test target configurations.

Stop linking frameworks to static libraries to avoid warnings with th…

Release 1.5.2

# gpg: Signature made Wed May  9 08:05:28 2018 PDT
# gpg:                using RSA key 01195BB315DDA856
# gpg: Good signature from "Samuel Giddins <segiddins@segiddins.me>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 7B19 37A9 CF66 AEF6 52C9  4090 0119 5BB3 15DD A856

# Conflicts:
#	spec/cocoapods-integration-specs

Release 1.5.1

# gpg: Signature made Sun May  6 22:18:59 2018 PDT
# gpg:                using RSA key 01195BB315DDA856
# gpg: Good signature from "Samuel Giddins <segiddins@segiddins.me>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 7B19 37A9 CF66 AEF6 52C9  4090 0119 5BB3 15DD A856

# Conflicts:
#	Gemfile.lock
#	lib/cocoapods/gem_version.rb
#	lib/cocoapods/generator/xcconfig/pod_xcconfig.rb
#	lib/cocoapods/generator/xcconfig/xcconfig_helper.rb
#	lib/cocoapods/installer/xcode/pods_project_generator.rb
#	spec/cocoapods-integration-specs
#	spec/unit/generator/xcconfig/xcconfig_helper_spec.rb
#	spec/unit/installer/xcode/pods_project_generator/pod_target_integrator_spec.rb
#	spec/unit/installer/xcode/pods_project_generator_spec.rb
#	spec/unit/target/pod_target_spec.rb

Do not include test dependencies input and output paths

(cherry picked from commit 781d5047)

# Conflicts:
#	spec/unit/installer/xcode/pods_project_generator/pod_target_integrator_spec.rb

Change generated asset catalog plist name

(cherry picked from commit c109b144)

# Conflicts:
#	spec/cocoapods-integration-specs

Do not force `[system]` value for custom module maps

(cherry picked from commit 644280b5)

# Conflicts:
#	spec/cocoapods-integration-specs

Remove [system] declaration attribute from generated module maps

(cherry picked from commit 0a93634a)

# Conflicts:
#	spec/cocoapods-integration-specs

Make modular header private header access consistent

(cherry picked from commit 56231f98)

# Conflicts:
#	spec/cocoapods-integration-specs

Fix assetcatalog_generated_info.plist path in copy resources phase

(cherry picked from commit 76c47a81)

# Conflicts:
#	spec/cocoapods-integration-specs

Prevent duplicated targets from being stripped out from the framework search paths

(cherry picked from commit 15df291f)

Always generate FRAMEWORK_SEARCH_PATHS for vendored_frameworks

(cherry picked from commit d4468d5b)

Fix static framework dependent target double linking 

(cherry picked from commit 8e0f3b09)

Fix modular header access to header_dirs

(cherry picked from commit 4d95ed04)

Wrap dummy source generation with a message

Do not crash when creating build settings for a missing user build configuration

Skip test file accessors for `uses_swift?` and `should_build?` methods

Move computing pod targets by config to the analyzer

Do not include test dependencies input and output paths

For performance, since the analyzer has the dependency cache

Refactor build settings generation to be memoizable

Fix typo