Modifiedd layout to work with 43-key keyboard, compiles.
adjusted the updating of the matrix, should potentially work
modified svg diagram
added key to produce parenthesis normally and brackets when shifted
edited pin layout description in teensy-2-0.md
unchecked copypasted comments
Readded the twi library

There was no real reason for it to be deleted in the first places
cleaned up qwerty layout file a bit