Mostly cosmetic enhancements of windows installer

- using the right icons in the dialogs
- cleanup of text formatting
- added help text for /D, /S and /? params
- commented out catalog directive in generated config
  this is also described in a comment
- fixes uninstall problem on win64

  Fixes: #49  : Install Parameters and Helptext for cmd installation
  Fixes: #121 : Deinstallation of windows installer works, but is not removed from the software list in windows.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>