major update to doxygen configuration file:

major update to doxygen configuration file:

1) update to doxygen 1.5.x style file, as used in trunk

2) tell doxygen where are header files are, so include-file processing can be done

3) make all macros that are used to define variables/functions be expanded, so that doxygen will properly document the resulting variable/function

4) make all macros that are used to provide the contents of a variable (structure) be expanded, so that doxygen will be able to document the resulting fields

5) suppress compiler attributes (__attribute__(xxx)) from being seen by doxygen, so it will properly match up function definition and usage (for an example of th effect of this, look at the doxygen docs for ast_log() from before and afte this commit)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@157104 65c4cc65-6c06-0410-ace0-fbb531ad65f3