Include request params in oauth header

Include request_params in the signature generation
pipeline.

This is necessary for GET based methods.
Enhance twr_object class

Pass request_params to oauth signature.

Use POSTFIELDS or HTTPPOST accordingly.

Pass error messages to transfer-failure events.
Add TwrError packages

Include basic error types.
Add TwrStatus class

Add TwrStatus class with basic methods:
* update
* update_with_media
* show
* destroy
* retweet
* retweets
Add basic TwrStatus test.