Try to make findadv more robust if not ignoring format

Try to make findadv more robust if not ignoring format

If searching for instance '.+' , the found string expanded
to the end of search buffer. So we have to replace
'.' with '[^\}]'.
Also all constructs like '[^abc]' had to be changed to '[^abc\}]'
to not go behind the actual format.
There is still problem using '*', but constructs usin '+' seem to work now.
('.*' finds everything from first char in correct format
 to (including) end of next format change
 while '.+' find _only_ characters in correct format)