This patch adds two functions to the macro language:
new_file_dialog(title[, path[, defaultName]])
Pops up a file selection dialog for choosing a new file. path is the initial
directory to start in - default is used if you specify "", default is location of
window running the macro. defaultName is the filename that should
appear pre-entered in the dialog.
exist_file_dialog(title[, path[, filter]])
Pops up a file selection dialog for choosing an existing file. path is
handled as above. filter is the filter to use for choosing which files to
display (e.g. "*.h").
BUGS: defaultName doesn't work. I'm not sure why, because I know that
the filename makes it to util/getfiles.c:HandleCustomNewFileSB.
Other than that I think it all works. Please test it out and comment on
what you like or dislike.