[NEW TYPE INFERENCE] Misc cleanups
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=76964606
[NEW TYPE INFERENCE] Only declare a namespace if it has no previous declaration
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=76973188
Make transpileOnly flag skip checks and optimizations
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=76990694