todo.rst: Add quicklist
todo.rst: Updated format, new todos
util.py: Add functions for interacting with AUR
logger.py: Add none attribute
status.py: Add basic output
package.py: Improve Package object system

* Use namedtuples for return types
* Add argument names to function calls
* Use the AUR API for getting package information such as version number.
* Expac is now used to check the package database instead of scraping calls to
  pacman -Qi.
* Fixed version comparison.
* package.packages() is now a recursive generator.
* Refactored the dependency script; removed support for optdepends.
* Removed uneeded exceptions in package.py
todo: Add new priorities