levensh suggest unresolved probe points

levensh suggest unresolved probe points

This patch adds Levenshtein suggestion to match_node::find_and_build().
Suggestions are made in three cases:
   - Unresolved double-glob (e.g. syscall.poen**)
   - Unresolved glob (e.g. syscall.poen*)
   - Unresolved no-glob (e.g. kernel.functoin("bla"))

Note that suggestions for globby functors are based on the prefix part
only (part of functor prior to the **) to increase meaningfulness.

Example outputs:

syscall.poen --> similar: open, chown, fork, iopl, mount
kernel.functoin --> similar: function, data, trace, mark, statement

syscall.poen** --> similar: open, chown, fork, iopl, mount
syscall.poen* --> similar: open, chown, fork, iopl, mount
syscall.*poen --> similar: open, chown, ppoll, capget, capset
syscall.**poen --> similar: open, capget, capset, chown, fchown

Non-globby functors in general give good results. Globby stuff can be
troublesome:

sys**poen --> similar: nfs, vfs, _nfs, _vfs, end