Refactoring infrastructure used for color palettes.

Refactoring infrastructure used for color palettes. These are now
managed by vtkSMGlobalPropertiesProxy class which is simply a proxy.
vtkSMParaViewPipelineController respects new hints defined in XML to
setup links with color palette properties on proxy construction.
vtkSMGlobalPropertiesProxy replace vtkSMGlobalPropertiesManager which
was a fake proxy, needed special handling and didn't work in
multi-server configurations.

Also refactored pqColorChooserButton. pqColorChooserButton now has
Qt-property API that is pqPropertyLink friendly. This makes the
pqSignalAdaptorColor class unnecessary.

Moving classes pqStandardColorButton and pqStandardColorLinkAdaptor to
deprecated. These are now replaced by pqColorChooserButtonWithPalettes
and pqColorPaletteLinkHelper.

TODOS:
+ Fix pqApplicationOptions to use the new color palette mechanism
+ Fix pqSaveScreenshotReaction for the same.
+ vtkSMGlobalPropertiesLinkUndoElement - leaving this for future since
this functionality is no that critical.

Change-Id: I577d7d12a4a02a550535dc963759d68e827964ff