Add support for building with Travis

- Add build script (.travis.yml) for travis-ci.org support.
- Updates android/build.gradle to make linter errors non-fatal.
- Adds script to launch and wait for emulator image.
Change 2014 to 2013 in Italian translation

This is still the 2013 version, so let's not get too far ahead of
ourselves!
Merge pull request #5 from tjohns/travis

Add support for building with Travis
Merge pull request #3 from tjohns/master

Change 2014 to 2013 in Italian translation
Adding missing copyright notice to .travis.yml.
Merge pull request #13 from btco/master

Adding missing copyright notice to .travis.yml.
Publishing the I/O 2014 source.
Merge pull request #14 from btco/master

Publishing the I/O 2014 source.
Adding hero image.
Merge pull request #15 from btco/master

Adding hero image.
Open source a bunch of source artwork
Merge pull request #16 from romannurik/master

Open source a bunch of source artwork
Restore scripts/wait_for_emulator.sh

This script is used as part of our test suite for Travis CI, and is
needed to prevent the build from failing. (Or to be more accurate, to
allow the tests to run at all.)
Remove emulator from L preview bit.
Fixed a string comparison.
Replace .commit() with .apply() in PrefUtils.java

Fix according to issue #20
Merge pull request #24 from seewes/patch-1

Replace .commit() with .apply() in PrefUtils.java
Merge pull request #18 from tjohns/master

Restore scripts/wait_for_emulator.sh
Merge pull request #21 from Lukas-Stuehrk/FixStringComparison

Fixed a string comparison.