changes text in Error and Warning bubbles to be selectable

Change-Id: I5cd838c470474442f0f2f6f73501430ff4f9b9f2
matching component documentation URLs with values in _messages file

Change-Id: Ibfdb1f9bf426fd62b67043e8610d46b72ac6d21f
adds glass panel for popup menus so that they auto close when clicking on blocks editor

Change-Id: I5998908f55b09db56f18ad7e78100e75976c4b3b
Add a new method of loading text (blocks and form) files.

Add a new method of loading text (blocks and form) files. This new
method computes a checksum (MD5) on the server and verifies it on the
client side in order to detect network “middle boxes” that corrupt
files in transit.

Change-Id: Iededd8d21c1cebe9ee322fcb498c890ea1589064