Call on...Changed-slots after real changing.

Prior the on...Changed-slots were called after changing the
value of the property but before recalculating qml-bindings
and before doing the actual change of the css-values. Now
the slots are called just after the actual change has
happened.
Fix font.underline to behave correctly if false.

The property font.underlined applied the css-value
'text-decoration: normal' if explicitely set to false. This
did not have any concequences as the correct value would be
'none' instead of 'normal'. So explicitely setting a text
not to be underlined (any more) was not possible. This
commit fixes that.
Use correct context for Component.onCompleted.

Prior for Components the context in which
Component.onCompleted was run, was always the outer context
no matter whether it was specified in the Component-file or
in the instanciating file. This commit fixes that by using
the current workingContext as intended.
Replace evaluatingProperties by evaluatingProperty

Prior evaluatingProperties was a stack used to store the properties that are
currently evaluated. Due to some other changes in the property-system it was
in fact impossible that more than one item was on the stack at the same time.
Thus this commit replaces the stack by a single variable evaluatingProperty
that holds either the property that is currently evaluated or undefined.
Fix mouse areas for IE.

IE does not handle mouse clicks to transparent divs, so with this change mouse
areas get a background color and we make it invisible using opacity as that
doesn't affect the mouse handling.
Add some little more documentation.

Adds some better documentation to the getter and setter functions of the
geometry-properties
Small refacture of the property-system.

This commit replaces the global registry of propertyUpdaters by a registry of
all properties. Now there is only one function updateProperty left, which gets
the index of a property in the global registry and updates that property. The
same change was made for the getter and the setter. This slightly improves
performance and makes the architecture slightly easier.
Remove trailing spaces and some wrong indentation.
Add a working signal-slot system.

This commit adds a signal-slot system for internal use and support to define
and use signals in QML. This commit makes 'createFunction' obsolete as it is
completely replaced by signals. Moreover with this commit I removed
QMLTransientValue as it seems not to make sense anylonger. (Why shouldn't the
propertyChanged-signal be emitted during animations? In Qt it is emitted.)
Fix the className DOM-Elements get.

For components the DOM-Elements should have their inner id, their outer id,
their inner and their outer type (=component name) as classes.
For example:

// main.qml
MyComponent {
id: test
}

// MyComponent.qml
Rectangle {
id: root
//...
}

The DOM-Element should now have as className "Rectangle root MyComponent test".
Prior only the inner id and the inner type was set as class. This is now fixed.
Secondly for Repeaters, if the delegate had no id, the children always had a
class "undefined". This is also fixed now.
Add element type TextArea.

Moreover this commit adds the font-property to the TextInput type.