Overhaul README.md

- Add English translation
- List more contributors
- Wording and formatting changes
apt-get update in travis
Merge pull request #162 from BoGoEngine/develop

Finish 0.4 cycle
HOTFIX: Engine name should be "bogo"
HOTFIX: skip-non-vietnamese should be true
HOTFIX: Config GUI not refreshing on config changes
Bump debian version
HOTFIX: Should create empty config file on first run
HOTFIX: Put default_config into bogo, not in ibus-bogo anymore
HOTFIX: GUI controller crashes on first run

The code to build inputMethodList read config file directly and failed
on missing keys.
HOTFIX: Should check Unity on every key press

There is just no other way, even though this is very inefficient. We
can't reliably check it at engine startup (IBus now uses single global
engine by default) and both the reset and disable signals aren't fired
when Dash is enabled. But the short-circuit nature of python's logical
"and" operator ensures is_in_unity_dash() is not called on other
environments.
HOTFIX: Controller.py still crashes
HOTFIX: Catch exception with os.environ
HOTFIX: Text expansion checkbox toggles UI disabled/enabled
HOTFIX: Bump version in sphinx
HOTFIX: Update docs with new images
HOTFIX: Controller should show first tab
HOTFIX: Remove dash version in debian/changelog, we are native
HOTFIX: Manually depend on Python >= 3.2 in Debian