Remove vestigial IDL assistant reference.
Update XML scanning for more recent IDL versions:
 - Prepend directory to keyword links
 - Work around exec commands now having type "pro"
 - Smarter location of files in Alias.xml, including
   class groups, spurious ../../path entries, and
   as a last resort, brute force directory search.
 - Report number of scanned items in idl_xml_rinfo.el
idlwave-online-help: direct entry option
Clean comments and definitions
Ensure a link file is set before normalizing 
keyword link to main routine.
Remove the IDL Assistant which last worked in IDL 6.3
Don't color the fringe for electric debug.
Doc/comments fixups.
Major re-organization and cleanup.

Supporting files added:
   menus, routine, scan, variables, binding, and complete.
Remove vestigial XEmacs and other unnecessary code
Comments
Create sintern type on idlwave load
add autoloads
Include arrow on stop line always.
Add new files to compile/install list
Convenience functions for routine entries
Correct help-with-topic topics
Implement new "idl.htm#path/to/file" method of linking
Switch idlwave.org -> github.com/jdtsmith/idlwave
Moved shell completion functions to -complete