Set the tightbbox for unparsed chords.

... to ensure that they get spaced correctly.
Fix Staff &lt;barLineSpan&gt; file tag:

With the 'new' XML reader, tag attributes have to be read before reading the tag main value.

For Staff &lt;barLineSpan&gt; tag, this has not been adjust yet.
fixing 2 mistakes in instruments.xml

and instr_language.xml
add svg icon engine
Merge pull request #355 from mgavioli/Fix_staff_barLineSpan_tag_reading

Fix reading Staff <barLineSpan> file tag from score
fix #20970 : Glissando collides with elements before note
Merge pull request #357 from Soerboe/fix20970_glissando-acciendental

fix #20970 : Glissando collides with elements before note
Merge pull request #356 from Jojo-Schmitz/instruments.xml

fixing 2 mistakes in instruments.xml
Merge pull request #349 from softins/layout-unparsed-chords

Set the tightbbox for unparsed chords.
gray out inactive icons
colorize toggled icons
try something new for breaks design
fix crash in text indent more, ordered list
add simple system bracket
missing icon in Style->Text
tune icon color
make breaks and spacer bigger
fix overlap of lines in break symbols
pressed buttons have white icons now
update note duration icons