Added bufferLine class.

The bufferLine class will represent one of the lines in the LCD screen,
limiting the amount of characters that can be seen at the time. The
class supports operations normally done in a terminal like environment,
like a moving cursor, and adding or inserting characters.
Added Tools.py module.

The Tools.py module will contain all sort of functions that would be
useful to have when programming the Raspberry terminal. Right now,
the only function in there is getch, which get a character from the
input.