Add number to default forward block in Turtle.
Add number to default forward block in Turtle.

git-svn-id: 2cf55447cea94972d775c94cce66c944ede0459c@656 c400ca83-b69d-9dd7-9705-49c6b8615e23

Khan/blockly,Khan/blockly,tobyk100/blockly-trunk,jadonk/blockly-bonescript,tjpalmer/blockly,tobyk100/blockly-trunk,tjpalmer/blockly,jadonk/blockly-bonescript,tobyk100/blockly-trunk,tobyk100/blockly-trunk