Remove leading "0x" when expanding octet types

Which is a simple patch now that the evaluation of casts avoids
printing && parsing of attributes
Check for unknown attr on the RHS
Checks for casts to differing sized attributes
Allow integer64 to be converted to ethernet
add const to cast
list may be unused, so mark it as such
Fix memory leaked at exit time
Doxygen
Remember which hex test failed
Add regression text for 0x prefix
Pre-parse static RHS of update section.

Because we can now do it, and it will save us time.
Add missing comment symbols in mysql.conf
Update to rlm_perl to also handle sub-sections in "config" section
Fix formatting in rlm_perl
\, --> , for consistency with everything else
Don't escape strings to / from Perl
Move DEBUG messages to RDEBUG

and clean them up
Document how the data is passed to/from Perl
Move example.pl to mods-config, and clean up the make file
Missed in last commit