New record modes and bugfixes

Fixes #58 #60, #61, #69 updated vendors and thanks to @johnmadrak-wobo, new record modes.

Bugfix release

Fixes #50, #52, #53, #54, #56 and better error messages.

You'll have to re-record your fixtures (just delete them) because the headers are now in their original format, not lowercased like before. A request might now not match against an already recorded one.