Merge pull request #1 from jjmartres/master

Update port index method
Change "Disk Usage" multipiler and unit ( % -> B ). And create new item "Disk Capacity", add it into graph as Y axis MAX value.
Add trigger for changes of Device Serial Number
Update README.md
Add a discovery rules for each CPU core, and split CPU-related items into a new template "ZBX-FORTINET-CPU".
Add some items for memory resources, and split Memory-related items into a new template "ZBX-FORTINET-MEMORY".
Add some items for firewall session(IPv6, session setup rate, diagnostic item), and split Session-related items into a new template "ZBX-FORTINET-SESSION".
Create a new template "ZBX-FORTINET-HWSENSORS", which discover and manage FortiGate hardware sensors.
Merge pull request #22 from kobbie/master

pull request for my modified zbx-fortinet templates