Eliminate the 2 second poll timer.

Eliminate the 2 second poll timer that was used to receive return
values and commands from the phone. Instead use a long lasting xhr
request that blocks in the Companion until results are available.

Change-Id: I9c829e7cc104612d360a2e98d3b9cd80945e0e79
Change how the UI Thread is invoked for repl code.

Have AppInvHTTPD arrange to run incoming code from the blocks editor
on the UI Thread instead of Scheme code in runtime.scm

Change-Id: Ibde8d681564d762ed3080c55e618fe9ac01093b4
Convert NanoHTTPD to use a ThreadPoolExecutor.

Use a ThreadPoolExecutor to handle incoming http requests rather then
spawning a new thread for each request. Get rid of the large stack
size thread groups, we don’t need them anymore. All Scheme operations
are now on the UI Thread which already has a bigger stack.

Change-Id: I20710b6d014001be54333a6a0f7bdaabd9c8d5ce
Update Companion Version (again).

Change-Id: Ia3656807ed7f93337464f3849f8ac9ee7c56e319
Prevent an error loading blocks with bubbles (comments) with Firefox.

Change-Id: Ide8bbf2c607cc157afaebec6ae2eb062d1d30eec