Add tests for hierarchical folder sorting
Increase the timeout on test_imap_mutation.js for slow servers
Fix creation of IMAP folders with parents
Make folder sorting obey the folders' hierarchy
Fix a bug in ActiveSync where the fake inbox's server ID to folder ID mapping never got updated.
Fix calls to MailUniverse._deferOp()
Improve folder type heuristics in IMAP by looking at the display name instead of the full path (necessary if folders like Trash are underneath Inbox)