64-bit compatible

tac_plus-4.5b5-5 was tested on Fedora10 64-bit and everything works very well. tac_plus-4.5b5-4 should work as well. The 64-bit compatibility changes were done in 4.5b5-4 and carried to 4.5b5-5. The next release is due out in a couple weeks. This release will incorporate all the issues found in 4.5b5-4 plus a few more improvements.