Add createMainContext method
Allow non-number identifiers

Like NSString
Satisfy the latest Xcode warnings
Remove the failing nsarray category to create va_lists
Update prefix
Update podspec, even though pod lib lint still fails
Remove the simple save

It only added in complexity
Allow the error to be accessed from the outside
Bump version
Merge pull request #6 from TwelveTwenty/core-data-modernizations

[wip] Add createMainContext method