tests: re-include examples/tcstdlib and examples/typeclasses

Both directories were being tested before I excluded them in
d0c2c3f. They are deploy-tc-only TC examples and pass under the
current build, so they belong in the example suite.

Author: strub

config/tests.config

@@ -8,7 +8,7 @@ exclude = theories/prelude
 
 [test-examples]
 okdirs  = !examples
-exclude = examples/MEE-CBC examples/old examples/old/list-ddh !examples/incomplete examples/to-port !examples/tcstdlib !examples/typeclasses
+exclude = examples/MEE-CBC examples/old examples/old/list-ddh !examples/incomplete examples/to-port
 
 [test-mee-cbc]
 okdirs = examples/MEE-CBC