Redundant/complex Example and Demo file hierarchy

Based on external feedback the examples and demos layout can be non-intuitive for the following reasons

• Not everyone knows the difference between demo and example in the first place
• Examples itself has demos subdirectory (under declarative)
• In the SDK all that is under 4.7 without clear info if (and which of) those examples work under lower Qt version targets (i.e. if someone opens an example with an 4.6.2 Symbian target)
• It is not clear for many that declarative actually harbors the QML examples

I would suggest reconsidering unifying/clearing up the layout to make it more newbie-friendly