Show active Decls.

Previously we only showed Decls which were entirely complete, but this
means that variables which are in the process of being initialized are
not visible in the state. Change this so that we can see the variable in
its uninitialized state.
Remove existing instrumented modules and execution traces before running tests.
Don't compare traces that are inherently variable.

For example, don't compare pointers/print_argv_envp-ok, because the execution
trace naturally depends on the environment of the test machine.