Added `module_name` attribute.
Fixed CHANGELOG.
Make `module_name` a root attribute.
Flatten multiple underscores to one when generating a C99 identifier.
Lint that the `module_name` is a C99 identifier.
C99 identifier conversion normalizes to latin.
Use a Regexp to lint the module name
Merge pull request #209 from CocoaPods/module-name-attribute

Added `module_name` attribute.