autoconf/automake environment and should always use provided configure.

  Updated to use libtool 1.2 (with FreeBSD3.0 a.out v. elf detection).
  Updated autoconf to 1.12 with sed patch (don't use stock 1.12).
  aclocal.m4 is built using automake's aclocal, v1.3.
  Updated mkdep to support libtool .lo files.
Updated automake provided macros for TERMIOS, STRTOD, MKTIME, PTRDIFF_T
Autoconf now checks to ensure C compiler supports ANSI C prototypes.
Updated make files templates.

Add basics of Kerberos detection.