krb5_encode_test.c (PRS): Add the -p option to krb5_encode_test to

krb5_encode_test.c (PRS): Add the -p option to krb5_encode_test to
	change the sample principal value (to test encoding of
	different krb5 principals).

ktest.c (ktest_make_sample_principal): Use krb5_parse_principal so
	that sample principal can be configured for different purposes.

krb5_decode_test.c (main):
krb5_encode_test.c (main): Check return value from krb5_init_context to
	make sure it succeeded.

Makefile.in (check): Set KRB5_CONFIG to $(TOPSRC)/config-files/krb5.conf
	so that the tests work.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@9412 dc483132-0cff-0310-8789-dd5450dbe970