Update Companion Version (2.11ai2, Version Code 212).

Change-Id: I1dba7a771a15907dde19d94165c1ab17fdd53b31
BuildServer: pre-dex the runtime libraries

Change-Id: If5b942939e55edd106978ee8a08699d91eb7b1df
Fix issue #668 by adding red error triangles to duplicate component
event handlers.

This version uses ":" rather than "_" as an internal separator
character to defend against problems involving names with underscores.

It also abstracts over error strings (for internationalization)
in blocklyeditor/src/warningHandler.js.

This version abandons the earlier notion of special treatment of
singleton components = components (like AccelerometerSensor) for
which there can be conceptually only one instance. In this version,
all component event handlers are treated the same way.

Care was taken to avoid quadratic-time determination of duplicates
that was a problem in an earlier experimental solution to this problem
and was unacceptable for screens with large numbers of component event
handlers. In this new submission, duplicates event handlers are found
in a process that is linear in the number of component event handler
blocks, and each such block runs a constant-time error check to add
(or remove) the red error triangle.

Change-Id: Id7b0a69a4faf9028b5f534de515201d5a680ad2a
Revisit issue 545: improved project menu option names

* Start new project" => "Start new project ..."
* "Import project to App Inventor server" => "Import project (.aia) from my computer ..."
* "Export project to local computer" => "Export project (.aia) to my computer"
* "App ( save to my computer )" => "App ( save .apk to my computer )"
* "App ( provide QR code )" => "App ( provide QR code for .apk )"

Change-Id: I9e2c32fe3c844762d71ab8dd4c932230c49dcdb7
Minor Wording Change.

Change-Id: I656a2c09346fb3c6a6b090e9137c46e4e3e89faa