Tests can't be run concurrently from different builds

[riastradh]

Describe the bug
The Heimdal tests bind to fixed port numbers during the test suite:

heimdal/tests/kdc/Makefile.am

Lines 49 to 56 in ca0e53b

	port = 49188
	admport = 49189
	admport2 = 49190
	pwport = 49191
	restport = 49192
	restport2 = 49193
	ipropport = 49194
	ipropport2 = 49195

heimdal/tests/kdc/check-cc.in

Lines 51 to 57 in ca0e53b

	port=@port@
	pwport=@pwport@
	kinit="${kinit} --password-file=${objdir}/foopassword ${afs_no_afslog}"
	kdestroy="${kdestroy} ${afs_no_unlog}"
	kadmin="${kadmin} -l -r $R"
	kdc="${kdc} --addresses=localhost -P $port"

Thus, if two instances of the test suite are run concurrently, they may conflict and tests may spuriously fail.

To Reproduce

1. Build Heimdal in two trees at once.
2. Run gmake check in both trees simultaneously.

Expected behavior
Concurrent runs of the test suite pass.

Note: This is an separate issue from a single instance of the test suite failing with parallel make jobs, e.g. gmake -j4 check.

[nicowilliams]

Yup. This is a problem. We really need to rationalize all the tests and have them automatically pick port numbers to use.