SERVER-15632 Clean up cursor in MultiHostQuery if parent op has expired

(cherry picked from commit 7a7febfe1acd236ea11677638c0a8d5ddc6ceba6)
SERVER-12058 Abort mongod before letting exceptions esacpe from logOp().

Letting exceptions escape from logOp() can lead to inconsistencies in the oplog.

(cherry picked from commit 8a47cfef3d41decde32b1a425229f1dc1c810f65)

Conflicts:
	src/mongo/db/repl/oplog.cpp
SERVER-13726 standardize timeouts for slower builders

(cherry picked from commit c6d257962c8ca192f795a74fff8a73f36d28f7f9)
Merge remote-tracking branch 'upstream/v2.6' into v2.6