Various additions (widget properties loading/editing, multitouch, viewport).

- look for patches only inside of "/sdcard/PdDroidParty" folder (speeds up boot)

- draw widgets in original pd coordinates (removed "patchwidth"/"screenwidth" and "height"s references from individual widget source)

- colors for slider, toggle, bang, canvas

- label pos and size for slider, toggle, bang, canvas

- thicker lines for slider, bang, toggle

- antialias main canvas

- set audio frequency to 44100

- runtime edit : parsing "pos", "color", "label" (...) messages ("label_font" message still crashes at the moment)

- "steady on click" behavior for slider ("jump on click" not rewritten yet ; maybe useless on tablets ?)

- improved "bang" message parsing (do not "bang" when receiving edit messages)

- "hold" parameter functionality for bangs (stay visually "banged" for a some millis)

- minimum android api modified from 5 to 8 in AndroidManifest.xml (just to be able to use some Pointer identifier functions...)

- multitouch improved by rewriting motion event management ;
	widget use now 3 different functions : touchdown(pointerid,x,y), touchup(pointerid,x,y) and touchmove(pointerid,x,y).
	This makes writing of these functions much simpler and efficient than parsing the same event for each widget.
        Also implemented pointer stealing by deepest widget, like in pd.

- viewport function : if a "Canvas" (Canvasrect in pddroidparty sources) has "ViewPort" as receive name, "pos" and "size_vis" commands sent to it will be used by the main patchviewer to rescale patch view. This makes possible to present multiple panels to user, all written into the same patch.

- "pure-widgets-demo" patch added into "droidparty-demos"