add addSchemeData and import/export methods
add import/export methods
replace add/remove buttons by a menu with add, remove, rename, import
and export actions
add import_export module
Merge remote-tracking branch 'upstream/master' into import-export-theme
remove a "print"
typo nl.po
better number matching for scheme
improve slexer documentation
Remove invalid headers from PO files. Fixes #200.
stub for settings version upgrade.

what needs to be done:
- use new and correct domain name in app.py
- implement the settings transfer in install/update.py
- when that works well, uncomment the two lines in install/__init__.py
settings upgrade

- use new and correct domain name in app.py
- implement the settings transfer in install/update.py
settings version upgrade

uncommented the two lines in install/__init__.py
solve problem with QSettings when calling session.py directly

the organization name and domain and the application name must be set
before calling QSettings()
Merge pull request #202 from dliessi/settings-version-1

complete the settings upgrade to version 1
Merge pull request #201 from dliessi/issue200

Remove invalid headers from PO files. Fixes #200.
regenerate lilypond data with 2.16.2
Merge branch 'master' of github.com:wbsoft/frescobaldi
preview-mode: Add debug-layout-options.ly base file

Main file that includes the individual debug modes.
Included as -dinclude-settings.
preview-mode: Initial infrastructure in command.py

When composing a command as preview compilation
add several items to it.