- use "lassign" instead of multiple "lindex" operations
- do not raise error on duplicate dependencies
- follow formatting conventions
- use common parameter definition conventions (get rid of old-style nonpos args)
- get rid of some more empty_string_p
- allow to upgrade basic startup files (openacs-4/tcl/*tcl)
   to be upgraded via "install from repository" by adding
   and after-upgrade callback to bootstrap-installer and
   copying the files from there.
- move initialization of nsv_arrays for apm to -init file in acs-tcl
   (as suggested by Peter Marklund, but never implemented)
- use double colon prefix rather than "global" statement
   to denote global variables
- bump version number to 5.8.1d3
- move initialization of nsv_arrays for apm
   from -proc file of bootstapper to -init file in acs-tcl
   (as suggested by Peter Marklund, but never implemented)
- protect rename of "exec" against multiple renamings
- bump version number to 5.8.1d3