* scripting_wizard: Make it possible to get or set the value from a wxComboBox
* scripted_wizard: Make it possible to create target wizard, without the need to add BuildTarget panel

> The old code had a requirement that target wizards must add a BuildTarget
  panel. This is not always convenient for wizard implementer, so I've
  made it possible to make a target wizard without the need to add a
  BuildTarget panel. When this is the case the wizard implementer has the
  task to fully setup the newly added target.
- scripted_wizard: Use nullptr instead of 0, when dealing with pointers
* compiler: resolve bug 19021, new compiler flags created from the per-project settings dlg are not saved to running memory
  See http://forums.codeblocks.org/index.php/topic,18019.0.html