Add ClassSubject.isAssignableFrom(Class<?>).
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74181039
Added @GwtIncompatible tag to ClassSubject.isAssignableFrom.

-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74208032
Add ClassSubject.isAssignableTo(Class<?>). Also make the test method names more consistent.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74218204
Widen StringSubject.contains(String) to CharSequence.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74218396
Deprecate legacy Truth APIs in MapSubject.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74251639
Improve checking of error messages in MapTest.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74252317
Reduce visibility of Truth's StringUtil
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74326391
Disambiguate subjects when they have equal toString() representations but
different class types.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74337717
Use getName() instead of getCanonicalName() (which GWT doesn't support).
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74342220
Add Subject.isSameAs() and isNotSameAs() to test object identities.

Also deprecates Subject.is() for real now that there are two tests
to see if objects "are the same".
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=74628823
Update Inventory removing StringUtil which is now private.
Reword error message to the common denominator between Java7 and Java8 messaging.
Merge pull request #131 from google/moe_writing_branch_from_af7bfcea01d76e072b166c6c874c749d11949623

Merge change from google, including a lot of movement towards the 1.0 final apis.