Implement "Show clef" in "Edit Staff Types" dlg box for all types, not only for TAB's
Presets: implements presets

*) for percussion staves
*) as a setting in instruments.xml
do not allow drum note dragging
fix #17940: setting distance between beam doesn't work
Make preset names translatable.
Bar lines: property defaults for span parameters (staves, from, to) depend on staff span and number of lines.
Align with recent commits.

It also fixes #20424.
initial: improve performance adding and removing KeySig
ChangeElement updates keymap for keySig change
TAB: fix cases of wrong positions of augm. dots with "Stems through staves" option
Merge pull request #281 from mgavioli/TAB_dot_position

TAB: augm. dot position when stems through staff
Merge pull request #272 from mgavioli/BARLINE_property_default

Bar lines: property defaults
Merge pull request #274 from mgavioli/CLEF_stafftype_dlg_show_clef

CLEFS: Box "Show clef" in "Edit staff types" dlg box
adjust 1line staff to use first line
Removed redundant <stafflines> tags from instruments.xml
Removed comments
Merge pull request #278 from mgavioli/Presets

Presets: for percussion staves and as instruments.xml setting
Merge pull request #280 from heuchi/keySig_improvements

Fix #20573 and improve performance of KeySig handling
fix layout of grace note hook
honor beam mode NO for grace notes
move ledgerline and stemslash into separate files