vesper_test: Made mu_assert not return, added mu_assert_abort for critical checks.
vesper_util: Improved code style in vsp_time.c.
vesper_test: Moved test_random into test_util.
vesper_test: Added test for vsp_error.
vesper_test: Added check if cmcp_message rejects invalid ID types.
vesper_test: Added test for vsp_time functions.