Search across full relative paths of files and dirs in Project Overview
When using the search in Project Overview, if any part of the relative path from the project root to the file / dir matches, then the item is included in the search results: for a project with a tree containing 'foo/bar.po', searching 'foo' will display 'foo/bar.po' and so will searching 'bar' or 'o/b' etc. This works into subdirectories, and also supports wildcards e.g. 'fo*.po' for our example above.
There are two other changes as well: enable alternating row colours because this is standard for other parts of Lokalize, and collapse directories when the search string is fewer than 3 characters, since we were already expanding directories by default for 3 or more chars.
Edited by Finley Watson