[addons] fix TranslateSingleString to be more robust to badly formatted strings
[pvr] fixes GetDirectoryFromPath() - don't consider slashes as first character
URIUtils::RemoveExtension didn't account for slashes after an extension, so could chop everything after the period in paths like /some/path.foo/some/other/folders/
Merge pull request #3670 from jmarshallnz/find_fixes

Find fixes