Even though the binary search requires expensive string comparisons,
there are just log(n) of them to find the tag in the workspace array
and the result is much faster than scanning the array linearly (this
of course works only under the condition that
len(source_file->tags_array) << len(workspace_array)
This is however satisfied for big projects (and doesn't matter for small
projects).
Also make the tm_tags_find() function more user friendly by returning
tagCount 0 when no tags found.
32a3dfab7f