This patch adds a field lines_not_ascii to the MenuState structure. The
nth entry is 0 unless the nth member of MenuState.lines has a non-ascii
codepoint in it.
All comparison functions (menu_match_cb type) take an additional
argument to tell them if the thing they are matching is not_ascii. They
can use this to determine whether to collate and case-fold the
input (for non-ascii strings), or whether to use strstr/strcasestr (for
ascii strings).
The change is not currently implemented for flex matching, due to my
laziness. However, it should be a simple enough matter to add.
For my large input of 400,000 lines, this reduces typical filtering time
to about ten microseconds from about 2 seconds.
