Bug fixes and improvements

• Uses the 'vert' feature in the GSUB table of TT/OT fonts to switch to appropriate glyph forms for vertical CJK text
• Textflow formatting: bug fixes
• Improvements for Tagged PDF output with Textflow
• Table formatting: performance improvements and improved output
• Relaxed version checking for ICC profiles after discussion with industry experts
• Performance improvements in several areas
• Minor improvements for XMP handling and PDF/A output
• Lots of other bug fixes and improvements, many of which are specific for a platform or language binding