gvle: fix the tuple editor dialog

(closes #184)
gvle2: add the new GUI
gvle2: toward a file system enabling plugs
gvle2: enhance the display plugin system

The display plugin chooser has been enhanced. The check box connected
to the loaded plugins a better maner.
gvle2: add the WP2
 = Task 2.1 - Fix port connect into coupled models
  - Fix in/out port to submodel
  - Add basic connection highlight
 = Task 2.1 - Fix context menu bug
  - Menu can cause a segault when port not connected (read of an empty list). Fixed
 = Task 1.1 - Migrate help support to QTHelp framework
  - Add a custom rendering widget for -text only- pages (HelpBrowser)
  - Copy help pages to standard html source
  - Add QTHelp project and collection
  - Add a basic Makefile script to rebuild help
gvle2: add pkgconfig configuration
gvle2 : add a build menu item
gvle2: fix the installer
gvle2: improve the installer for gvle2