Who knows how long the tests for containers have been broken. They
haven't bitrotted, however.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Fixes failures when you have unbuilt libraries in your validate tree.

This means we can put package-specific tests in the repository for the
package, rather than putting them in the testsuite.  There should be a
.T file to go with the tests, in the same way as for other tests in
the testsuite (but this could be in addition to a standalone test
driver that works with Cabal's 'setup test').

Add a Makefile here.

Use makefiles in the subdirectories to ease running the test driver in
a subdirectory.  It can be run in the following ways:

 	make		-- run all the tests in the current directory
 	make verbose	-- as make test, but up the verbosity
 	make accept	-- run the tests, accepting the current output

and you can also set some variables on the command line, eg.

	make accept TESTS=arr001  -- accept an individual test
	make EXTRA_HC_OPTS='-v'   -- extra flags to the haskell compiler
	make CONFIG=<config>	  -- use a different test config

this will all go in the docs at some point.