front end / back end ajax

added login bar at the top
added db file
added front end buttons ajax scripts for user session
added back end routing and functions for user session
improved front end

- moved db files to db folder
- placed all on click code into their own respective functions (to clean
up clutter)
- created a message-box that comes up to prompt user
- upon submitting login, back end sends message back to front end. front
end javascript decides what to do for each message. whether to tell user
to try again later, or that their account doesn't exist. or to just say
that they're logged in.
- after submitting log in form, javascript ajax communicates with back
end to set up session variable, to finish "logging in",
more front end UI interaction

- added register form box, account settings box, that come upon clicking
register button or account settings button
- added jquery event listener and animations for register form box and
account settings box interaction
Merge pull request #7 from nklnkl/dev

Dev