Move AFP dbpath from share to service setting

Ticket:	#4997
Catch up latest changes in AFP sharing/services

Ticket:	#4997
Data migration needs to be within dry_run block
Catch up the docs with AFP db path change
Catch up API unit tests with AFP db path migration
Work around /bin/sh behavior of single quoting output of commands.

This was blowing up the command that was using the output of previous commands as arguements.

Ticket: #5010

Fix by:	delphij
Use proper netgraph module (not gif, socket!)
Add python serial module.
Add field for http proxy

Ticket:	#4866
Update API docs including http proxy field
Add gc_httpproxy field in unit tests
Revert "Add python serial module."

This reverts commit c3587a23bed095f674b6268ac2fa0720dcd1bda6.