Allow hex input for known answer tests
Closes #49
cleanup and documentation of test generation
closes #50 and closes #51
small changes
Merge branch 'newTestConf' of github.com:GaloisInc/hacrypto into newTestConf

Conflicts:
	callsha/callsha.c
	callsha/callsha.h
	callsha/tests2/C_tests/SHA256_NSS_KAT.c
	callsha/tests2/C_tests/SHA256_VST_KAT.c
	callsha/tests2/C_tests/SHA256_sodium_KAT.c
	callsha/tests2/C_tests/run_tests.c
	callsha/tests2/C_tests/tests.h
	callsha/tests2/SHA256_compare_in
	callsha/tests2/SHA256_compare_out