Get list of attachments (containing id, name, content type & size) for ticket
Adds a test for get_attachments
Adds method for retrieving ticket history in short format
fix more compatibility issues with Python 2.6 and 3.2

- fix decoding of received message
- binary result for attachment content
- maps to lists for python 3.2
change merge_ticket to support RT4 API
add edit_link call to replace buggy edit_ticket_links
test merge_ticket and edit_link methods
Adds ability to pass custom query to search method.
Merge remote-tracking branch 'github/pr/5'

- merge Stewart Perrygrove contribution with list of attachments
Merge remote-tracking branch 'github/pr/6'

- merge Stewart Perrygrove contribution with short format history
Merge remote-tracking branch 'github/pr/7'

- merge Stewart Perrygrove contribution with custom query to search
  method