* src/devices/grohtml/html-table.cc: Fix column width calculation.
(html_table::set_linelength): Don't add 1.
(html_table::add_indent): Don't subtract 1.
* tmac/html.tmac: Set default page offset to zero.
Make groff emit ` ' for `\ ' and `\~' if `-Thtml' is used.
* src/roff/troff/node.cc (space_char_hmotion_node::tprint,
unbreakable_space_node::tprint): New functions.
(troff_output_file): Make space_char_hmotion_mode::tprint and
unbreakable_space_node::tprint to friends.
* src/roff/troff/node.h: Updated.
* font/devhtml/R.proto: Add ` ' at position 0xA0 (as defined
in the HTML standard).