I noticed commit db3b531e2cab765a00475054d2e9046c9d0437d3 in the history
where Simon added a bunch of "static" qualifiers. That suggested that
consistently marking internal functions "static" is desirable, so I
tried a build using GCC's -Wmissing-declarations, which requires prior
declaration (presumed to be in a header file) of all global functions.
This commit makes the GTK build clean under GCC's
-Wmissing-declarations. I've also adding "static" to a few obviously
internal objects, but GCC doesn't complain about those so I certainly
haven't got them all.
I'm about to have a need to sort an array based on auxiliary data held
in a variable that's not globally accessible, so I need a sort routine
that accepts an extra parameter and passes it through to the compare
function.
Sorting algorithm is heapsort, because it's the N log N algorithm I
can implement most reliably.
