Log Message:
update to 2.12.2
This is a major release. Significant changes include:
* calc may be built with static or dynamic shared libraries
* overhauled Makefiles to use system targets
  - replaced compiler sets with host targets
  - targets include: linux, OS X, FreeBSD, simple, default
  - many changes to Makefile variables
* calc source static and extern variables declared with CPP symbols
  - to make it easier to compile under certain Windoz environments
  - to assist those who are developing a multi-threaded calc lib
* calc library makes it easier to control parse and scan messages
* added Makefile.simple for hosts without GNU Make
* added custom registers
  - when calc is run with the -C flag
* dropped support of md5 and sha-0 hashes
* calc supports real and complex exponentiation bases and exponents
  - i.e., 2.5 ^ 3.5, 0.5i ^ 0.25, 2.5 ^ 2.718i, 3.13145i ^ 0.30103i

added TEST_TARGET