When the wrap mode is used, after each tag a newline is started. Also the
html is indented, which can be configured by the parameters indent_base,
indent_base, indent_char. The parameter indent_base specifies the width
the first tag should be indented with, while indent_step specifies the
increment of the indent when switching to a child tag. The character,
that is used for indenting is taken from indent_char. (It could also be
a string longer than a single character).
This aguments can't be set by the user, but are hardcoded (by now).