Barlines: span attributes were not read back correctly from file.

Probably a left-over from the switch to XmlReader.
Merge pull request #261 from mgavioli/BARLINES_read_span_attributes

Barlines: read span attributes
TAB: with "stems beside staves" option, slashes (for slashed minims) and dots were in some cases positioned wrongly.
Merge pull request #263 from mgavioli/TAB_fix_dots_and_slashes_in_stems_beside_staves

TAB: fix dots and slashes in stems beside staves
change map iterators to auto
use system font to display the UI
fixes for workspace; some palette tweaking