tdb: build and run unit tests in tdb/test/

tdb: build and run unit tests in tdb/test/

Now we can build the test binaries: the CCAN style is to compile
everything called "compile_ok*.c", compile and run everything called
"run*.c", compile, link with the module, and run everything called
"api*.c", and link any other C files (presumably test helpers) into
all the tests.

Unfortunately, actually passing that between the various parts of
wscript is painful, so I open-coded the names.

Also, the tests expect to be run in a (temporary) directory they can
pollute, with the test directory found in test/ (to find the canned
TDB files, for example).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-User: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-Date: Tue Feb 14 06:53:46 CET 2012 on sn-devel-104