Added a few enhancements to make it work for more people.

1. Updated header to use /usr/bin/env to look for python instead of
specifying python2.6.

2. Updated mhiWrap to use DESTDIR at the replacement string for the
provided dir.  Previous value referred to /home/pj.

3. Updated mkMhilinks in several ways
3a. Uses sed to replace DESTDIR with $destdir in mhiWrap
3b. Copies mhi.py and configobj.py to $destdir
3c. Symlink mhi to mhi.py
Copy readlisp.py to $destdir.