2.2.1 — Migrated implementation to NSInputStream

• Complete refactoring to use NSInputStream instead of direct use of NSData (Thanks to @kcharwood - #28)
• Some other code refactoring to split the code in categories and make it clearer
• Some API changes to make OHHTTPStubs to fit the new possibility of setting both requestTime and responseTime.
  • Old API is still there but deprecated, and will be removed in next major version
  • To convert to the new API, you will mainly simply:
    • extract the responseTime: parameter to a method call of its own (return [OHHTTPStubsResponse responseWithData:data statusCode:code responseTime:time headers:header]; will become return [[OHHTTPStubsResponse responseWithData:data statusCode:code headers:headers] responseTime:time]; etc.)
    • convert responseWithFile:filename to responseWithFileAtPath:OHPathForFileInBundle(filename,nil)