It's better to color some invalid things as if valid than the other
way around. So, as strings can validly contain any number of double
quotes, just accept *anything* between the delimiting double quotes
and demand that the closing quote is followed by whitespace or EOL.
The new option 'set selectedcolor' applies to marked text, to the
currently selected file in the file browser, and to the highlighted
match during interactive search-and-replace.
Extend get_softwrap_breakpoint() to break softwrapped lines on
whitespace when a flag is set. This flag is controlled by the new
rcfile option "atblanks". The '>' characters marking two-column
characters at the edge of the screen are disabled when it's on.
If get_softwrap_breakpoint() can't find whitespace in screen range, it
will break the line on the screen edge. (In this case, a blank can be
on the last column of the screen, but text can't, so that a blank on the
last column doesn't become invisible and possibly break the display.)
This fulfills https://savannah.gnu.org/bugs/index.php?49959.
Requested-by: Nicholas Boel <axxisd@gmail.com>
Negative arguments of 'fill' are bright green since a few commits.
So now color all valid numeric arguments in that same style -- the
yellow was hard to see on a dark background anyway.
Also, color a zero tabsize as invalid.
