Merge pull request #266 from PeterBjuhr/master

wip musicXML export
reorganise simplemarkdown
wip simplemarkdown
simplemarkdown starts working...
use correct split() args
wip simplemarkdown, fix bugs
better and better...
add iter_split() function, makes stuff look simpler
make iter_split and iter_split2 distinct functions
smarter iter_split and iter_split2

both will never yield None but an empty string instead
iter_split2 will not break arguments on the first separator when there
is no second separator.
header
some doc love
yielding two empty strings not needed
remove superfluous method
oops
started iter_split

dont allow missing ending separator
handle list prefixes with no text better
handle header better
some versions of Frescobaldi's icon for Mac OS X

frescobaldi-shadow.svg: most Mac hi-res icons have a shadow
frescobaldi-bigF.svg, -thickF.svg: "F" more visible in low-res versions
Mac .icns icons file

1. export frescobaldi-shadow.svg to PNG at sizes 512, 256, 128
2. export frescobaldi-bigF.svg to PNG at size 32
3. export frescobaldi-thickF.svg to PNG at size 16
4. create frescobaldi.icns from the PNGs with Apple Icon Composer