Update JavaWriter to the latest.

Specifically this fixes a problem with handling fully-qualified class names which are nested under 'java.lang' but not directly in the 'java.lang' package (e.g., 'java.lang.ref.WeakReference').
Merge pull request #422 from square/jw/update-javawriter

Update JavaWriter to the latest.
Add JDK 8 to Travis build.
Prepare version 1.2.2.
[maven-release-plugin] prepare release dagger-parent-1.2.2
[maven-release-plugin] prepare for next development iteration
Fix up a case where we report errors poorly when state is wrong, usually becuase of inconsistency in what is passed in to ObjectGraph.create().
Make the test a little more explicit.
Merge pull request #428 from cgruber/improvederror

Fix up a case where we report errors poorly when state is wrong, usually...
Update to Android worker.
Merge pull request #436 from square/jw/fix-travis-ci

Update to Android worker.
Use Types.isSameType for comparing TypeMirrors.

The documentation on TypeMirror.equals states "Semantic comparisons of type equality should instead use Types.isSameType(TypeMirror, TypeMirror). The results of t1.equals(t2) and Types.isSameType(t1, t2) may differ.".
Merge pull request #433 from square/jw/types-comparison

Use Types.isSameType for comparing TypeMirrors.