SERVER-14778 hide _native_function and _native_data properties of injected native functions

(cherry picked from commit 6042e906fdd907d53b8231749422f786f19114d8)
SERVER-14205: fix error reporting in IndexCatalog::createIndex

(cherry picked from commit 8fc8bc9a86711bb9ea41887d2f88362353dc3062)
Merge remote-tracking branch 'upstream/v2.6' into v2.6