Use print function for Python 3 compatibility

The print function is available all the way back in 2.6, and using it allows the bot to run under Python 3 (which I use extensively), so I hope you don't mind me including it.
Fix broken conditional statements

This is what happens when you commit without testing, kids.
Work on multiple machines
Use os.path instead of manually handling paths
Fix typo

...again.
Add back local login info for testing

Turns out it's hard to test things when you can't login.
Use os.path more
Add a simple gitignore to filter out login info
Close file handles; Python 3 support
Remove useless interp function

Turns out dropping into the interpreter inside a function like this only
gives you the context of the function, not the main program.
Remove useless update_mostrecent function

There's no need to keep the most recently submitted post in a message to ourselves, we can just check the bot's submission history.
get_mostrecent from submission history

...instead of the inbox.
get_submitted() doesn't take arguments like that
Add a post_link convenience function

Takes a reddit url, and posts it in /r/airz23 (is that where the bot should post?). Optionally takes a title for the post; if this title is left out, the title of the url will be used.
Merge pull request #2 from AGSPhoenix/master

Add a whole lot of stuff