Prefix catch all error responses to make message recognizable

Summary:
It is currently hard to detect whether a test failed because of a legitimate
error by a developer or because something is going wrong in selendroid
internals. This diff marks error responses from the server that indicate
something has gone wrong in the internals of selendroid.

Test Plan:
```
$ mvn clean install
...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] selendroid ......................................... SUCCESS [  0.105 s]
[INFO] android-driver-app ................................. SUCCESS [  2.107 s]
[INFO] selendroid-server-common ........................... SUCCESS [  0.890 s]
[INFO] selendroid-server .................................. SUCCESS [ 16.272 s]
[INFO] selendroid-grid-plugin ............................. SUCCESS [  0.826 s]
[INFO] selendroid-common .................................. SUCCESS [  0.968 s]
[INFO] selendroid-standalone .............................. SUCCESS [ 15.209 s]
[INFO] selendroid-client .................................. SUCCESS [  0.564 s]
[INFO] selendroid-test-app ................................ SUCCESS [  4.431 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
```

Reviewers: mkonicek

Reviewed By: mkonicek

Differential Revision: https://reviews.facebook.net/D28929
Update AUTHORS

Adding missing authors.
Added folder monitoring capability and fixed emulator launching problem.
- The folder monitoring allows users to add one or more native android
apps on fly and selendroid immediately signs and adds these files to
the app store so they can be used without restarting the node.
- Adding one seconds wait before calling "isDeviceReady" to avoid the
command sent too quickly while the emulator still starting and not ready
to receive any commands

Signed-off-by: Binh Vu <bvu@paypal.com>