Default editor fonts

[Torsten]

I remember a thread where we discussed if the editor default fonts which
are provided by the qsci-lexers (among them proportional fonts) should
be replaced by our own defaults. I submitted a patch at
https://savannah.gnu.org/patch/index.php?8246
with a new version of the default-qt-settings.in where the editor-lexer
settings are included. The font name and size for the lexers are set to
the already available  macros %DEFAULT_TERMINAL_FONT% and
%DEFAULT_TERMINAL_FONT_SIZE%.

AFAIK the following fonts can be regarded as standard on the different
platforms

Windows:     Lucida Console
Unix-Like:   Courier (Monospace?)
Mac:         Monaco

and are chosen in configure.ac depending on $host_os.

Torsten