basic setup corresponding to file import
First version
accidentals supported
Basic durations supported
tuplets supported
note about developing under windows in readme dev
improve preview mode tool layout

while the checkable groupbox is a nice solution, it looks too heavy
on some platforms, e.g. by its bold text. Also the checkbox did not
align with the other checkboxes on many gui styles. Finally I let
the curent gui style decide on the layout margins which looks better.
move all the credits to frescobaldi_app/credits.py
bump version to 2.0.12-dev
edit->select block finally implemented
write much shorter
select block: put cursor at beginning

this is more intuitive; in many cases one wants to extend the selection at the start, e.g. to select a full expression after having selected a block of music that's the argument to a \command.
more elegant

select_block can now use any cursor to perform its trick
update the edit dialog to remove shortcuts conflicts
display shortcuts conflicts directly in the dialog.

shortcuteditdialog take 2 new optionnal arguments:
* conflictCallback: a function or methode that return a shortcut
conflict name.
* cbArgs: the optional arguments to pass to conflictCallback
add a _num attribute
comment lines that remove the Shift modifier

with its lines when a special character is pressed (é, è, ç), the
equivalent of a QWERTY keyboard is sent.
add "setShortcuts" method
replace "editAction" by "findShortcutConflict" and "removeShortcuts"
add the findShortcutConflict method