Merge branch 'release/v0.20.0-rc1'
Merge branch 'release/0.20.0'
Drop pre from README.md install instructions
Merge branch 'release/0.20.1'
Adjust version and tag in Podspec for release
Merge branch 'release/0.20.2'
Fix Xcode 5 -Wdocumentation warnings from mismatched parameter names/returns
Merge pull request #1453 from erikcharlebois/development

Fix Xcode 5 -Wdocumentation warnings from mismatched parameter names/ret...
Fix retain cycle (issue 1404)
Merge pull request #1458 from mirego/fix-issue-1404

Fix retain cycle (issue #1404)
Fix memory leak in iOS 5 and 6 when calling "- [NSCachedURLResponse data]"
Merge pull request #1459 from mirego/fix-memory-leak-ios

Fix memory leak in iOS 5 and 6
RKResponseDescriptor: equality specs added
RKResponseDescriptor: isEqual: implemented
RKRequestDescriptor: equality specs added
RKRequestDescriptor: equality implemented
Descriptors equality: check class of specified object
Descriptor hash method
Bump Ruby version to p429
Merge pull request #1462 from AlexDenisov/descriptors_equality

Descriptors equality