SearchPlusPlus

Update version and changelog.

More accurate messages for Mark and Show when there are null matches.

If current line indicator is highlight background, in search results list change to 3 pixel frame when current line is a header line to avoid unreadable text.

Slight change in vertical alignment of symbols on search command buttons to get them more centered. This is empirical: no logical reason I know that it should be this way.

Better (maybe) symbol for in Selection.