Pseudo modification of views and triggers

Dear Dave,

I implemented pseudo-modification of views based on the function example.
Pseudo modifiation is carried by a simple DROP /CREATE in both cases. This
was pretty easy : I just had to copy and adapt your code...

This seems to work fine. I will do the same for triggers and commit tomorrow
after testing.

I enabled pseudo-modification features only for >= 7.3. IMHO this is better
to avoid confusion (or we would get questions like "why can we modify views
and not functions?" from 7.1 users).

One question : why did you keep the .ddl compatibility with previous dll
versions? It is not necessary as the .dll is loaded at every startup. No?

Cheers,
Jean-Michel