#576 Fix for fr2590274

[Cary R.]

This patch adds the functionality requested in feature request 2590274. It adds new information that says if a module/scope is using the default or a timescale defined time unit. This information is then used in the three places where delays are elaborated and if it find that the user has both a default and `timescale defined delay it prints a warning message and recommends they use -Wtimescale to solve the problem. The patch and three examples are attached. The last (c) needs to be run with -gspecify. All three produce the same output and a gold file is included.

This needs to be applied to both development and V0.9.

[Cary R.]

Patchm, example and gold files.

[Stephen Williams]

Applied to git master.

[Stephen Williams]

Applied to git v0_9-branch.