Update licensing information in documentation to match currently available licenses

Licensing page in Qt 5.4 documentation should be updated to match our current license offering (http://doc.qt.io/snapshots/qt5-5.4/licensing.html).

For example:
-> We do not have license called 'Qt Commercial', we should list Enterprise, Professional and Indie in the first bullet list in addition to Community
-> It would probably be good to list 'Community' edition instead of the 2 separate LGPLs in the first bullet list as there is option to take it under LGPLv3, or parts of it with v2.1
-> Webshop should be added to the 'Purchasing and Sales Information' in such a way that it is easy to see also that option