added icons to Composite pipeline widget to hide/show pipelines or controls (phi, theta, time, ...).
Refactored to create tools toolbar and widget for composite image stack.
refactor rendering widget.
Refactored pipeline widget.
Created a higher level tools widget that corresponds to the composite tools widget, but for the static image stacks type.
Refactored field control widget to control widget.
Should be pipeline widget part for search view.
Refactored field model to control model. The term fields is overly used in Cinema, and field is typically used to define a simulation variable.
Renamed visualization canvas widget lit to light.
Merge pull request #59 from Kitware/tools-control-widget-improvement

Tools control widget improvement