Added pause function

simple set the rendering loop on hold.

io.pauseFramerate(bool); // true to stop, false to go on
Private variable not accessable. Missing in fork.
Get Group

Functionality to get objects from group.

io.getGroup('TAG','CANVAS',from,to);

Only tag is necessary. Tag and canvas should be familiar from
addToGroup etc. "from" / "to" allows to reduce the returned object as
needed. If "from" is given and no "to", it will automatically fetch the
first value beggining at "from"
Added alpha functionality

Possibility to use ioObject.styles.alpha = 0.25; to make object
transparent.
Multi-Row text

Added functionality to use floating text
Fix getCellAt for non square grid

x is a column number and y is a row one.
merge Bahlor's additions, add quick demos, improve file structure
update readme
update readme
update readme
update readme
Merge branch 'patch-1' of https://github.com/judu/iioengine
fix getCellAt for rectangles
update deletions
fix default group check
add Acceleration, ball bounce and hello iio demos
Updated ball demo
correct notes
update drag and drop demo info
add drag and drop demo