Fatal assertion fixups
SERVER-16173 Rewrite repair for KVEngines
SERVER-16367 Add versioning information to WiredTiger indexes
SERVER-13679 Make RecordId and DiskLoc separate types
SERVER-16222 Turn prefix_compression on by default for WT indexes
SERVER-16258 Remove our strnlen and audit all callers

Our strnlen differed from the c standard by using int rather than size_t and
return -1 rather than the max length when not finding a NUL byte.
SERVER-16254 Clean up wording of invariantOK message
SERVER-6981 Remove maxPasses limit and unify capped no-space errors
Remove BSONObj::hash() and BSONObj::md5()

They were unused in incorrect.