[qmozcontext] Remove redundant autoInit attribute from QmlMozContext

Scheduling QMozContext.runEmbeding to next event loop iteration in
the constructor of QMozContext guaranties that gecko startup
will happen in the next iteration. Thus the attribute autoInit in
QMozContext::GetInstance() and explicit call to
QMozContext::GetInstance()->runEmbedding(0) before
starting Qt event loop are redundant.
[qmozcontext] Drop QmlMozContext in favour of global QMozContext instance

QmlMozContext is a declarative workaround for QMozContext singleton.
Until there is a better support for singletons in QML make an instance
of QMozContext to be global object in QML.
Semantically a global instance makes clearer suggestion that it's
a singleton than an attribute of a QML component.
[qmozcontext] Avoid QThread subclassing

Starting from Qt 4.4 QThread subclassing is considered to be
a bad practice: a QThread should only manage a thread, not process
data.
Setup embedding explicitly in main()
Merge pull request #13 from rojkov/cleanup1

Make sematics of QMozContext clearer.
Added simple API for notifying engine about first UI initialized state,
Added qtest-qml unit tests
Updated unit tests in order to run it separately for each case in qtest-qml
Added about:mozilla view test
Enable Async video back, 854539 landed to upstream
Disable Qurl from user input because it clear invalid urls, and we want to use keywordURL feature
Handle IME type and setup related Qt input hint
Added more tests for input context
Added Test helper components
Added missing tests components
Added String based observe API, prepare for history direct notifications
Removed useless observe
Added basic scroll unittest
Fixed multitouch handling with Gecko Shell handler
Removed check for Update event