anchor.diff:  Object Selection
   ----------------
   
  -Using alt-i and alt-a, you can select some text object, the starting
  -point is always the last character of the selection.
  +Some keys allow you to select a text object:
  +
  + * _alt-a_: selects the whole object
  + * _alt-i_: selects the inner object, that is the object excluding it's surrounder.
  +            for example, for a quoted string, this will not select the quote, and
  +            for a word this will not select trailing spaces.
  + * _[_: selects to object start
  + * _]_: selects to object end
  +
  +After this key, you need to enter a second key in order to specify which
  +object you want.
   
    * _b_, _(_ or _)_: select the enclosing parenthesis
    * _B_, _{_ or _}_: select the enclosing {} block
    * _[_ or _]_: select the enclosing [] block
    * _<_ or _>_: select the enclosing <> block
  - * w: select the whole word
  - * W: select the whole WORD
  -
  -When it makes sense, _alt-i_ selects the inner object and alt-a the whole
  -object. For example _alt-i_ will only select the inside of the parenthesis,
  -for words, the difference between _alt-i_ and _alt-a_ is that _alt-a_ also
  -selects the following blanks.
  + * _"_: select the enclosing double quoted string
  + * _'_: select the enclosing single quoted string
  + * _w_: select the whole word
  + * _W_: select the whole WORD
   
   Registers
   ---------
  
positive.code: 
  existing highlighters are:
  
   * +highlight_selections+: used to make current selection visible
   * +expand_tabs+: expand tabs to next 8 multiple column (to make configurable)
   * +number_lines+: show line numbers
   * +group+: highlighter group, containing other highlighters. takes one
              parameter, <group_name>. useful when multiple highlighters work
              together and need to be removed as one. Adding and removing from
              a group can be done using
              `:addhl -group <group> <highlighter_name> <highlighter_parameters...>`
              `:rmhl  -group <group> <highlighter_name>`
   * +regex+: highlight a regex, takes the regex as first parameter, followed by
              any number of color spec parameters.
              color spec format is: <capture_id>:<fg_color>[,<bg_color>]
              For example: `:addhl regex //(\h+TODO:)?[^\n]+ 0:cyan 1:yellow,red`
              will highlight C++ style comments in cyan, with an eventual
              'TODO:' in yellow on red background.
  
  Filters
  -------
  
negative.code: 
   * +preserve_indent+: insert previous line indent when inserting a newline
   * +cleanup_whitespaces+: remove trailing whitespaces on the previous line
         when inserting an end-of-line.
   * +expand_tabulations+: insert spaces instead of tab characters
   * +regex <line_regex> <insert_regex> <replacement>+: when the current line regex
         and inserted text regex matches, replace insereted text with the
         replacement text. Capture groups are available through $[0-9] escape
         sequence, and cursor position can be specified with $c.
   * +group+: same as highlighters group
  
  Hooks
  