Add a new version of JavaWriter that allows for writing to different parts of the compilation unit simultaneously.  Then, use it in code generation in Dagger 2 code.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70279532
Merge pull request #31 from google/moe_writing_branch_from_7d4dc76e9606dadbb9d55181582b9d9c51e4810b

Add a new version of JavaWriter (temporarily inside dagger)