fix #23366: more fixes for capitalization

and some more fixes.
another forgotten one
Merge pull request #736 from Jojo-Schmitz/23366-orig-texts

more fixes for capitalisation
install FreeSerifBold on Mac OSX
fix #14764

convert qDebug();abort() to qFatal() and if(cond) abort() to
Q_ASSERT(!cond), esp. for the benefit of Windows, where it is impossible
to set a breakpoint on the abort()
Also modernizing mscoreMessageHandler() and making it more informative
by adding file, line and function to the output.
changing all assert() to Q_ASSERT()

except for thirdparty/portmidi/
Merge pull request #737 from Jojo-Schmitz/14764-qDebug+abort-to-qFatal

fix #14764
break in gui and no-gui case
Merge pull request #738 from Jojo-Schmitz/nogui

break in gui and no-gui case
option to disable loading of parts and images
fix #7805 : copy and paste does not preserve stem direction for beamed notes
change semantic of tick2 for line spanners
add vtest for ottava
update Gonville
Merge pull request #740 from AntonioBL/beam_direction_paste

fix #7805 : copy and paste does not preserve stem direction for beamed notes
simplify TextLine, use only text and drop symbols
several fixes for translations
simplifying translation by joining multi part strings

Correcting some apparent errors and adding some missing translations in
the due course
'untranslate' some strings from the debugger
adding/removing colons in some dialogs

and making insert measure dialog similar to append measures dialog