Revert "CXX-324 fix additional tests"

This reverts commit 211b1f49f7ec9adaf1419d075b05d9d0404e12f0.
Revert "CXX-324 do not depend on static init for WriteConcern"

This reverts commit aadc8d081511d96e05cf8e819203d0593b276c4f.
CXX-270 change mongoclient target to driver, add examples to test target