Cleanup ghostscript-gnu-commfont and related CJK font support meta ports.
Changes include:

• Set WITH_GHOSTSCRIPT_GNU forcibly.
• Use PostScript virtual fonts to handle CJK CID/TT-CID emulated fonts. CIDFnmap still works but when a font is both in Resource/Font or Resource/CIDFont and in CIDFnmap, the former entry will be used. For the actual font mapping, see files in Resource/CIDFont/*.
  
  So, note that you need to remove (or rename) the virtual font if you use CIDFnmap for the moment. This is still a transitional measure and more consistent font management thoughout the ports collection should be added later.
  
  This is just an internal structural change; default font mapping has not been changed.
• Add Chinese font support to print/gsfonts (but no dependency added).