Transferred control of the pen into a tool class
Implemented basic functionality of a TextTool (now just able to set cursor).
Stamp function in pixmap (sub-pixmap insert).
Init pixels to OFF in pixmap
Bug fix in Pixmap(PImage) constructor: was using bad values
Une keyTyped() instead of keyPressed() (to allow for unicode characters).
Cosmetic change
Reworked with memory string (not tested for RTL).
Allow backspace.