#42 Improve CifWriter/CifResource writing performance, especially when using platform paths

• Best to review per commit.
• Changes:
  • Renamed StreamCodeBox to AppStreamCodeBox. Improved its comments.
  • Add new OutputStreamCodeBox. It has better performance, especially since it doesn't flush per line, which is expective for OutputStreams created for Eclipse platform paths/URIs.
  • CifWriter and CifResource use the new OutputStreamCodeBox for better performance. Probably not really noticeable for CifWriter.

Closes #42 (closed)