When called from a working directory different from the directory
where the bootstrap script is located, make the bootstrap script
only work on its own directory and not whatever the current working
directory just happens to be.
Let the autoreconf tool handle the sequencing of tool calls.
The autoreconf tool has been dealing with calling tools like
aclocal, libtoolize, etc. quite well for about the last 20 years.
This keeps the "bootstrap" script around to keep the old way
of calling bootstrap working, i.e. maintain compatibility with the
existing workflows.
