pretty-printing body of the commit that is stored in non UTF-8
encoding did not work well.  The early part of this series fixes
it.  And then it adds %C(auto) specifier that turns the coloring on
when we are emitting to the terminal, and adds column-aligning
format directives.

* nd/pretty-formats:
  pretty: support %>> that steal trailing spaces
  pretty: support truncating in %>, %< and %><
  pretty: support padding placeholders, %< %> and %><
  pretty: add %C(auto) for auto-coloring
  pretty: split color parsing into a separate function
  pretty: two phase conversion for non utf-8 commits
  utf8.c: add reencode_string_len() that can handle NULs in string
  utf8.c: add utf8_strnwidth() with the ability to skip ansi sequences
  utf8.c: move display_mode_esc_sequence_len() for use by other functions
  pretty: share code between format_decoration and show_decorations
  pretty-formats.txt: wrap long lines
  pretty: get the correct encoding for --pretty:format=%e
  pretty: save commit encoding from logmsg_reencode if the caller needs it