Readability: clean up indentation.
Readability: [more] consistent use of blank lines; remove or add trailing blank(s).
Consistent variable ordering; remove unused 'empty' member variable; rename ctl_env to defaultModulePath and initialize inline, eliminating initKnob member variable and instead using makeKnobs() member function for a runtime test.
Inject a little ILM style: no virtual qualifier in implementation files on virtual methods.
Use knob_changed() more in the style of the examples in the NDK documentation.
Promote user_module_paths to NukeCtlIop member variable, and various path- and transform-reading functions in the global namespace to member functions.
Fix from Matt Plec of the Foundry for handling Set Module Path and Module Path controls.
Add check for ShowPanel event.
Merge branch 'feature/Nuke_module_path_cleanup' into ctl_1.5_rc