doxygen parsing flow

http://www.stack.nl/~dimitri/doxygen/starting.html#extract_all

1. execute the special commands in documentation. the special commands are listed in:
http://www.stack.nl/~dimitri/doxygen/commands.html
the documentation is always specified by documentation block: http://www.stack.nl/~dimitri/doxygen/docblocks.html#specialblock
somtimes, it can be specified at other place:
http://www.stack.nl/~dimitri/doxygen/docblocks.html#structuralcommands

2. remove the line start by some whitespace followed by one or more asterisks(*) and then optionally more whitespace.

3. Keep all resulting blank lines to make documentation readable.

4. Create links.
1) for the words corresponding to documented class, execpt the words is preceded by a '%'.
2) for the members corresponding to some pattern, http://www.stack.nl/~dimitri/doxygen/autolink.html

5. Interpret HTML tags, http://www.stack.nl/~dimitri/doxygen/htmlcmds.html.

Tips:
.% can be used to despress the auto links for the words of ducumented class.
.It can be documented with documentation block or at other place.