Enhancement - Hooks

- Implemented all command hooks.
- Implemented several field hooks.
- Implemented several task hooks.
- Reorganized event validation code.
- Finalized Hooks -> API::call* mechanism.
- Implemented several hook unit tests.
- Corrected unit tests that didn't specify rc.hooks=on.
- Corrected builds that include Lua.

src/tests/hook.pre-exit.t

@@ -34,6 +34,7 @@ use Test::More tests => 7;
 if (open my $fh, '>', 'hook.rc')
 {
   print $fh "data.location=.\n",
+            "hooks=on\n",
             "hook.pre-exit=" . $ENV{'PWD'} . "/hook:test\n";
   close $fh;
   ok (-r 'hook.rc', 'Created hook.rc');