Use a #local variable in compiler generated timestamps

[vyzo]

Currently it is module/path#module/path::timestamp, intending to avoid conflicts with user variables.

As @feeley suggested, there is a better way to do that: use a # local variable in the fully namespaced name.
So it should be module/path##timestamp and there should be any danger with user variable conflicts.

TODO:

• update the compiler generated module timestamp name