Reworded warning for SERVER-8113 to avoid misleading users.
s2*cursor now use same covering size determination.  speed up near search
validate s2polygon loops and s2polygon proper while building it
old point implies radian distance, new point implies meter distance
SERVER-939 abilitiy to distribute collections in a single db

Port tests from d_chunk_manager_tests.cpp for metadata_loader_test.cpp
SERVER-939 abilitiy to distribute collections in a single db

Fix memory leak when error is encountered while creating a CollectionManager
SERVER-8210 Cannot insert new documents to mock server after doing a query

Changed implementation to use vector instead because BSONArrayBuilder cannot be modified once done() is called on it.