Merge libxo-0.8.2:

• xohtml: Add "-w" option to pull support files from gh_pages
• Add "upload-xohtml-files" target to publish support files in gh_pages/
• add HISTORY/AUTHORS section to man pages
• xohtml: Add div.units as standard CSS text
• Don't treat values as format strings; they are not
• add "-p" to "mkdir -p build" in setup.sh
• add test case for {U:%%} (from df.c)
• detect end-of-string in '%' and '' escaping
• make xo_simple_field, for common simple cases
• xohtml: nuke "n" in "echo" commands
• rename "format" to "fmt" for consistency; same for "str" to "value"
• update test cases

Submitted by: phil