Support loading SSH keys from memory
Minor cleanup
Move import
Allow paramiko to do key type checking
Raise last exception if no valid key
Refactor key loading + add password support to in-mem keys

Re #909
added Travis CI pin
added Travis CI pin
Print out the task method signature when `fab -d <task_name>`.
Calculate args_without_defaults from args_with_defaults.
Add tests for task details.
Monkey-patch inspect.getargspec for Python 2.5

because the return type changed from plain tuple to namedtuple since 2.6
Attempted fix re: #593
Changelog re #593, fixes #593
Merge branch '1.6'

Conflicts:
	docs/changelog.rst
Tone down the nohup pitch in FAQ, it rarely works nowadays
Merge branch '1.6'
Force jinja2 to be 2.6 so it works on Python 2.5
Kinda figured I'd run into quote problems
Minor language tweak re: fabfiles.