Fix and enhance the box plot and chart

Fix the problem with the position of Y axis: long labels were trunked.
This position was fixed, it is not flexible depending the size of the labels.

Add new functions to the chart API to allow manipulation of series
by id (vs by name).
Add support for manual plot labels setting.
Enhance the boxplot displacement, it now correctly follow the mouse
without ugly jumps.

Change-Id: I400cd064616f7b93415e17db9749d709ea2f7345
Make it possible to override ClampPos.

This is needed to add support for editing control points where Y is not
clamped to [0,1].

Change-Id: I96c36c49d51964ac19a657dffa9cd8184e8b23f2
Merge topic 'enable_subclassing' into master

59b7ad11 Make it possible to override ClampPos.
change signatures for wrapping

Apparently functions whose signatures contain vtkSmartPointer
are not wrapped into python.  Change such methods of
vtkTreeHeatmapItem to contain ordinary pointers instead.

Change-Id: Ic98311c10f1e7a99fb4ad071d3981e4febb0604e
Merge topic 'treeheatmapitem_wrapping' into master

6d501034 change signatures for wrapping
Merge topic 'FixAndEnhanceBoxPlots' into master

cee00a0e Fix and enhance the box plot and chart