Generalize displaying t/nil values of info params
Add support for debug messages
Add variables for "None" and "Unknown" strings
Move defining AUR URL to the top level

Remove `aurel-filter-aur-url' and define AUR URL before displaying info.
Set aurel-info-mode before printing info

Set `aurel-info' early to allow functions that print info parameters
rely on this variable.
Add support for interacting with AUR account
Support displaying "voted"/"subscribed" parameters
Add interface functions for voting/subscribing
Inherit aurel-info-mode-map from special-mode-map
Update README
Update version (0.5) and package commentary