Change checks to be strings instead of JavaScript types.

Changing type checking in preparation for Blockly push.

Change-Id: I8c65df58c8fa13340a3425c257c941066d44721c
allow component blocks to output "component" for type checking, in addition to their type name

Change-Id: I7c5420bdc0b1dd6470d5504864b84c8e7a3fd286
add get block below for blocks and parameters

implementation of this needs to change based on http://trac.appinventor.mit.edu/ticket/410 but will do later due to time constraint

Change-Id: Icbe7ad4220d4ce5e4c3970cd4a7c03bde3e136d7
add default arguments to for block
add default aruguments to random integer from block
It is now consistant with App Inventor (classic)

Change-Id: I8fc4def283d43c5070a27b72644e14efc323fd30