String fixes

- Clarify wording in a couple places
- Fix missing 'not' and remove non-standard dashes
- Standardize on single-quote for strings in strings

qa/qa_utils/stdstream_line_reader.cpp

@@ -73,7 +73,7 @@ IFSTREAM_LINE_READER::IFSTREAM_LINE_READER( const wxFileName& aFileName )  :
     if( !m_fStream.is_open() )
     {
         wxString msg = wxString::Format(
-            _( "Unable to open filename \"%s\" for reading" ), aFileName.GetFullPath().GetData() );
+            _( "Unable to open filename '%s' for reading" ), aFileName.GetFullPath().GetData() );
         THROW_IO_ERROR( msg );
     }