BOMify blockly-all.js

Add bomify.py script used during build to add a UTF-8 Byte Order
Mark (BOM) to a file used for bockly-all.js.

Change-Id: I31019ed4c3fe213d5fb01952b83b6a68ad86b374
Eliminate unused/unneeded security constraints.

Eliminate unused/unneeded security constraints in order to reduce the
number of URL Map entries to below 100 so newer versions of the App
Engine development environment can be used to upload new code to App
Engine instances.

Change-Id: I2f15bc2fcfafe0c02d218e429dd9ef4485b89d05