Release 1.2.7 of the Checker Framework and Type Annotations compiler

[Werner Dietl]

We have released a new version of the Type Annotations (JSR 308) compiler
and the Checker Framework.
 * The Type Annotations compiler supports the type annotation syntax that is
   planned for a future version of the Java language.
 * The Checker Framework lets you create and/or run pluggable type-checkers,
   in order to detect and prevent bugs in your code.  

You can find documentation and download links for these projects at:
http://types.cs.washington.edu/jsr308/

Changes for the Checker Framework

Regex Checker:
  Add basic support for the concatenation of two non-regular expressions
  that produce a valid regular expression.
  Support "isRegex" in flow inference.

Framework improvements:
  Declaratively add stub files to a checker using the new @StubFiles
  annotation.

Internal bug fixes:
  Respect skipDefs and skipUses in NullnessFlow.
  Support package annotations in stub files.
  Better support for enums in annotation attributes.
  Cleanups to how implicit receivers are determined.

Changes for the Type Annotations Compiler

No changes in functionality.