Remove (most of) the contents of the Installers/WinInstaller directory

[Russell Taylor]

The packaging on Windows is handled by CPack now, so most of this is obsolete. There are just a few files that are still required (a quick look suggests these are: License.rtf, qt.conf & the scons-local directory).

[Russell Taylor]

This commit didn't make it in automatically:

commit 9e486abcbcb0759ca9191bddcadf97b8473cce3f
Author: Russell Taylor
Date: Tue Sep 24 13:23:12 2013 -0400

Re #8011. Remove majority of contents of WinInstaller directory.

This mostly relates to the old way of building Windows installer packages. Now it's all done with CPack. Just a few things remain that are pulled in by the CPack packaging.

[Russell Taylor]

This is probably best tested by someone who's familiar with the internals of the Windows installer building and deployment just in case I've removed something that's used somewhere obscure (I judged what to keep by searching the repository for mentions of the WinInstaller directory). Then it's a case of downloading and installing a package from one of the ​develop branch builds and checking that everything starts up OK.

[Martyn Gigg]

The package looks fine. It installs and starts okay. The "About Mantid" box shows all of the images, which shows that the plugins have loaded correctly and therefore the qt.conf is correctly shipped. The rest of the stuff wasn't used.

[Martyn Gigg]

Merge remote-tracking branch 'origin/feature/8011_clear_wininstallers_directory'

[Stuart Campbell]

This ticket has been transferred to github issue ​8856