New branch. Test character sprite added.

Not really sure where I'm going to go with this branch yet. Going to try
controlling a character, possibly collision detection within a level.
Kitten class added.

Running Kitten.py runs a test application that draws the sprite. Running
Main still does what it did in the master branch.
Merged refactored Sfc_Game.py from Master
Major update to Sfc_Game

Sfc_Game.py updated to use the concept of "dirty rectangles" to redraw
only what has changed, rather than redraw the entire screen each time as
before. Note that for now there is effectively no difference from
before, as the program is still the panable background, and thus the
entire screen is redrawn anyway. BUT the approach will make further
development much cleaner.
Livvy can now be controlled.

The kitten sprite can now be moved around by the arrow keys, while the
background is now stationary.

There are kinks to work out: I don't like the way things are being drawn
to the screen by Sfc_Game but I haven't yet found a fix.
Livvy sprite size changed slightly.

Also added new image for a test of switching sprite images when movement
occurs. Nothing has been coded for that however.
Character sprite image changes upon movement.

Custom (awful) background also created.
Kitten speed changed, sprites resized/updated.
Sprite image updates; FPS change
Character control change.

Speed in Y now slightly faster than X.
Added bug list and docs folder.
Added to bug list.
Large fix to way sprites are dealt with in code.

Better use now made of Pygame built-in functionality for sprites. The
issue of passing the screen to GameSfc for drawing is now fixed.
Fixed sprite control issue described in bug list

Also slightly modified control state so KeysDown is implemented LIFO.
Correct order of keypresses is now guaranteed if read from the left.
Sfc_Game change to Sfc_Background

GameSfc class changed to Background. The "use one surface for
everything" idea worked well in my older Pygame apps, but it doesn't
play well with sprites.
Background class better reflects its new scope.

Dirty rect's removed from background, as built-ins in Sprite class can
automatically redraw needed parts of background after a sprite moves.
Also panning of the background has returned, using WASD
Bug list update (removal)
Main: Sprite groups now in dictionary

Should allow for easy access of a particular group later on. Will be
needed soon to give Background info about the player character's
position
Background now pans with sprite movement.

Still lots of problems to work out. I think a new Camera module to
handle a lot of this stuff might be good. Next step is to fix lack of
free movement at beginning and end of level.
Doc'd Kitten.py