Improved performance of Definition

1) Improved finding locked_deps efficiency in coverage_local_specs
   from O(N^2) to O(N).
2) Improved specs_changed from O(N^2) to O(N)
Use inject instead of each_with_object for 1.8.7 compability
Fixed #2994 regression with the resolver

We now keep track of conflicts we have encountered
to resolve the dependencies better
Improved the performance by avoid a O(n) lookup in states
Use cached_path for built-in gems if the gem exists locally
Added the test to check if install --local doesn't fetch specs remotely
shell escape bundle open args :O
editor might need shell parsing
had no idea that in-array splat was 1.9
update changelog [ci skip]
load rubygems before rspec
Version 1.6.3 with changelog
Merge v1.6.3

Conflicts:
	CHANGELOG.md
	spec/spec_helper.rb
fix retry of fetch for protected gem servers
use case for double-class check
store svn ref in lockfile (fixes #3080)
unbreak lockfile spec