Cherry-pick some libc++ fixes from: https://jira.mongodb.org/browse/SERVER-11070
Upgrade from gtest 1.6.0 to 1.7.0
Need to include locale.h for libc++
Fix #506: Usability request - add initial curly braces to command bar
Fix #505: OS specific keyboard shortcut tips
Fix #500: TTL index should allow expiry of 0 seconds

Docs example:
http://docs.mongodb.org/manual/tutorial/expire-data/#expire-documents-at-a-certain-clock-time
Merge pull request #525 from stennie/issue-524

Fix #524: OS X build fixes for XCode 5 / libc++
Merge pull request #528 from stennie/issue-506

Fix #506: Usability request - add initial curly braces to command bar
Merge pull request #529 from stennie/issue-505

Fix #505: OS specific keyboard shortcut tips
Merge pull request #530 from stennie/issue-500

Fix #500: TTL index should allow expiry of 0 seconds