Add different point symbols for QgsRubberband.

[m-kuhn]

As discussed in the previous pull-request, this adds the possibility for several different point markers.

QgsVertexMarker should be subject to be removed as soon as this pull-request gets accepted.

[NathanW2]

Any objections from anyone to merge this one?

[mhugent]

Isn't it necessary to consider also the pen width in qgsrubberband.cpp:482?
Otherwise it looks good to me, +1 for merge

[m-kuhn]

I was thinking about it, but it wasn't considered before for outlines of
polygons and lines neither and I did not notice any artifacts so far.
But if it's necessary, please tell me and I'll include it as well.

Another thing is, that when using with polygon or line, the rect which
is considered for update has a "buffer" of half an icon size around it,
but that's a slight performance hit at max.

[mhugent]

Please add the pen width, it is saver. I think it was just luck that it worked so well with the rubberband so far.

[m-kuhn]

Done.

Note:
If there are any more changes required, I might have a little time tomorrow and after that I'll be unavailable until Jan 3.

[mhugent]

Merged, thank you Matthias.

[NathanW2]

That was close. I was just about the merge this pull request :)

[m-kuhn]

Marco, FYI:

http://hub.qgis.org/issues/6987

Looks like we got already bitten by the pen width, depending on the client (graphics driver or so...)