Prevent double-deletion of managed objects
Merge branch 'master' into coredata-issue

Conflicts:
	MantleTests/MTLManagedObjectAdapterSpec.m
	MantleTests/TestModel.xcdatamodeld/TestModel.xcdatamodel/contents
Clarify the situations in which MTLJSONAdapter ignores keys

Mentioned in #137.
Merge pull request #2 from github/master

Sync github/Mantle
Add system requirements and installing information
Improved formatting in README
Merge pull request #139 from akashivskyy/readme-installing

Add installation guide to README
Added Error when the JSONDictionary received is nil
Check if error if not NULL before using it and fix a comment
Update the description of a test to the new behaviour
Fixing missing instancetype on 10.8
Adding documentation for -isEqual and -description
Improving documentation
Improving documentation again
Fixing typos
Added the new behaviour to the documentation
Fixing TomDoc style
Minor fixes in syntax and descriptions
Merge pull request #146 from github/isequal-docs

Adding documentation for -isEqual and -description
Merge branch 'master' into coredata-issue