Changes:
  - Removes unused languages that bloated the package
  - Moved check for running application to after the install
    directory request so that it checks for the correct path
  - Moved the uninstall of the previous version to just before
    installing the new one so that we only uninstall if we are
    overwriting in the same location.
  - Shows progress during uninstall of the old version rather than
    being silent.
Refs #13341

A couple of lines were added as an additional check but NSIS requires you
to tell it how many lines to skip in an if statement so this needs
updating too.

Unfortunately this is yet another modification to the NSIS template, but theres not other way to get this done with the current CMAKE version 2.8.1

Also put shortcut on start menu.

 Tries to figure out if this is the users first time install.

According to NSIS, the order of the arguments is important and the ExecWait
will cancel after the copy unless the arguments are swapped over. This way
the uninstall should happen in place without any copy.

Quite a pain to get this right. Performs an automatic unistall as part of the setup. Will also now chain through slient mode options through to the internal uninstall command. Also uses wait version of exec to ensure sequential uninstall/install. Works in admin (command line mode) and via the GUI now.

re #3115. Merged with Michael's changes and set-up so that the system path can be modified and reset by the installer on windows.