Update build scripts.

Arrange for normal build (ant without arguments) to include debugging
flags, in particular line numbers. This is how we have been building
production installations for about a year (via -Ddebug=true).

Normal builds will now automatically build the AI2 Companion App if
necessary (it won’t be rebuilt if it exists and no dependencies have
changed).

Added build target “noplay” to perform a build that explicitly doesn’t
build the Companion.

Added build target “installplay” which first uninstalls the Companion
from a connected phone and then installs the newer version. This means
that it will work without worrying about keystore files etc. This
isn’t part of the default build because it will fail if a phone is not
connected via USB. Note: Newer phones can use adb’s ability to connect
over the network as well.

GWT invocation changes: Removed build targets for ie6 and ie8. They
just take up time to build and blockly doesn’t work on ie6 or ie8
anyway. Updated GWT build to build “pretty” which generates more
readable javascript, which makes debugging easier (we minimize for
production). Also changed the loglevel to INFO so there is feedback
displayed during the build which otherwise would just sit for a long
time in the “YaClientApp” stage.

Change-Id: Id563fa1a631db2cdd2baaf1a4a52165744ed54cd
Add Support for connecting to a device via USB Cable.

There is a new “Connect To” menu choice of “Connect via USB.” As its
name implies, you can use this to connect via a USB Cable. You still
have to install the Companion on the device, but you don’t have to
start it manually (it doesn’t hurt if you do). The connect menu choice
will start the Companion for you.

Updated aiDaemon (you will need a new setup package) to properly close
file descriptors prior to invoking “adb.” This means that you can kill
and restart aiDaemon without difficulty.

You can now use the Emulator even if you have a phone plugged
in. Previously this led to the blocks not being properly loaded to the
Companion in the emulator.

Change-Id: I9d21e01ef1df8b955d60a8472ce4be97a6e60515