Adding "end level screen".

Still need to fix player movement after "complete" status is "true".
Fixed y collision behavior, end level movement

When player collides in an upward direction, yVelocity reverts to 0.
When level is completed, player can no longer do movement.
Still need to add actual end of level logic, including either loading a
new map to going to menu.
Outlined planned logic for end of level.
Elaboration of routes of level end.
Started on support for maplists.

Creating maplist to allow for easy custom selections of maps.
LPMapList now loads properly.

Playstate will use an LPMapList to get the first map to load. Nothing
else going on there yet.
Starting on level progression and state changes

Outstanding bug on initialization. Specifically, things aren't
initialized when they are made and this is bad practice. Causing things
to not go well when switching between play and menu states.
Fixed keysDown issue, added initializations

- keysDown was sticking around too long after keypresses, causing
"newstate" to be set too quickly agian.
- Initializations thrown in. Probably need to fix where they are called,
since right now they are only called... after the state is no longer
used. Meh.
Added version tagline to menu screen.
Added "use strict" and other JSLint bits

No changes needed to make "use strict" work, so that's cool.
Using .hasOwnProperty instead of in to be more explicit about the object
involved.
Converted some double equals to triple equals.
Starting work on making map scrolling work.

Hit some early pitfalls, I think I know what needs to be fixed but I
don't have time to do it right now. Will look at it over the weekend
maybe.
Initial map scrolling (X direction only)

Still rough - need fine tuning to allow easy+consistent edge touch.
Check LPTiledMap line 269, as example. Also a lot of outdated comment
that should be removed but, for now, aren't because it's late.