Sprite.say/think and Sprite.colorEffect

added colorEffect to Sprite
made Sprite.say, Sprite.think draw word bubbles on canvas
misc organization and typo correction
documentation changes
Stage.timer() decimal seconds, dynamic # of timers

added stage.addTimer()
documentation updates to Stage.timer stuff
fixes for facing/seesOnSides, & speedForVector
added Sprite.stamp(x,y);
recenter p.imageMode after Stage.drawTiled();
say/think scroll with character
Sprite.draw() dialog works better
adding Sprite saturation & brightness effects
various visual effects improved

Was altering source array, oops. Now duplicates costume to new PImage
and modifies that.
Sprite.touching* no longer detect hidden Sprites
revert to simple sample with pens
making new dev. branch to keep master in good shape
formatting
Merge branch 'master' into dev
added motion trails to stage
Revert a6d9544..2df0924

This rolls back to commit a6d9544b3798f9496e9799d8d8cb752a98042092.
visual effects looking good
minor changes to sample prog