Improved source export from Frescobaldi, please test

[Urs Liska]

To anybody who runs Frescobaldi from the Git repository:

I'm working on an improved source code export from Frescobaldi (which became necessary because the WordPress editor for the LilyPond blog scrambled the HTML code).
While I'm not finished with it yet and will provide a better and unified user interface I would like the underlying export "engine" to be tested as thoroughly as possible.

So anybody who has access to Frescobaldi's Git repository and is willing to share some testing time, please:

- add my fork as a remote (addresses to be found at https://github.com/uliska/frescobaldi)
- pull the test-html tag and try it out.

There are several menu items (currently, they will be unified in one dialog):
File->Export->
  - three different versions (plus style sheet)
Edit->
  - three different "Copy As ..." commands

exporting/copying is possible
- as HTML source code
- as formatted text (copy only-> to be pasted in rich text editors like OpenOffice)
- using style sheets or inline formatting

I'm especially interested in any corner cases coming from different selections (start from a line, start from a token, beginning in the middle of a token, single/multiple line etc.)

See also:
https://github.com/wbsoft/frescobaldi/issues/156
https://github.com/uliska/frescobaldi/commits/test-html

Please do _not_ base any work on anything on that branch. As I'm working on different computers I often need to push 'prematurely', and all is subject to rebasing at any time.

Thanks for any feedback
Urs