Add per-spec static library targets

Static library targets are created for each combination of user-target
and spec dependency.  This addresses issue #841, although likely not 
entirely.
Identify copy build phase by spec name
Only add a single Manifest.lock phase when dealing with multiple specs
Add specs to libraries for non-integrated targets
Merge branch 'master' into dedicated-targets
Support xcconfig files per Podfile target

Xcconfig files are generated for every library target and target 
defined in the Podfile.  However, only the Podfile target xcconfig 
files are added to the user project.  This required tracking all the 
libraries as well as the Podfile targets through the installation and 
integration procedures.
Merge branch 'dedicated-targets' of https://github.com/jasl8r/CocoaPods into jasl8r-dedicated-targets

* 'dedicated-targets' of https://github.com/jasl8r/CocoaPods:
  Support xcconfig files per Podfile target
  Add specs to libraries for non-integrated targets
  Only add a single Manifest.lock phase when dealing with multiple specs
  Identify copy build phase by spec name
  Add per-spec static library targets
Merge branch 'master' into dedicated-targets

* master:
  Release 0.19.1
  [Integration] Update version in fixtures
  CHANGELOG [skip ci]
  [TargetInstaller] Create unique hash instances for the build settings
  [Generator::Xcconfig] Add inherited to GCC_PREPROCESSOR_DEFINITIONS
  Changelog [ci skip]

Conflicts:
	lib/cocoapods/generator/xcconfig.rb
Add Pods integration library

Adds the libPods.a and target derivatives back as targets in the Pods 
project.  The integration libraries are simple containers linked with 
all of the per spec libraries to create a single library for the user 
project to link with.  The xcconfig file for the integration library 
merges namespaced config settings for all dependent specs for use by 
the user project.
Remove nil specs and pods from installer rep maps
Don't install library without target definition
Keep shell script phase simple and static

The copy resources shell script phase was previously updated every 
time the pods were changed.  This moves the updates to the integration 
library copy resources script and restores the original static single 
line from before the per pod library code.
Only integrate with targets that require it

This restores and merges the original code for determining if a 
user target requires integration.
Bug fixes and cleanup
Update test specs

Many changes are simple API changes, generally centered around the 
renaming of Library to Target.

There are also a lot of additional stubbed or test classes added to 
accommodate for the fact that real Pods installations always have one 
or more integration libraries each with one or more per spec 
libraries.
[Integration] Update fixtures
Merge branch 'master' into dedicated-targets

* master:
  [Rakefile] Perform setup on for integration only if needed 2
  [Rakefile] Don't set the git user as not needed anymore
  [Rakefile] Perform setup on for integration only if needed.
  [Doc] Make clear that an error occurred in a pre/post hook.
[Integration] Update fixtures 2
Move integration library linking outside of target integrator

The target integrator is only run when libraries are being integrated 
with user projects.  The Pods integration library needs to be 
updated, linked with the spec libraries, regardless of user 
project integration.
Quote copy resources scripts