Merge pull request #178 from gladhorn/master

Cleanup example common dirs
Add installer script and data.

To create installers the Qt installer-framework is needed.
Currently building installers is only tested on windows.
Merge pull request #179 from gladhorn/installer

Installer
Installer fixes

Get mkspecs right (not everyone has the same user name as me).
Get headers right (before it only installed the forwarding headers).
Show windows style paths in installer (c:\... instead of c:/...).
Allow spaces in target dir.