#send_file indifferent :status option
Use #Integer (thank you, @rkh)
Add support for supplying options to `static!`, enabling the use of custom status codes, etc.

Add test case highlighting the breakage when attempting to use `send_file` with a specific status code. refs sinatra/sinatra#749
Merge pull request #790 from GateGuru/feature/enable-options-in-static-method

Feature/enable options in static method