Uptime, SSH-Connected users, CPU AVG

=== NEW ===
Added Uptime to index,
Added SSH-Connected usercount to index
Added CPU-AVG (1/5/15) to index
Added SSH-Connected userlist to System Info (w output)

=== RPIApi New ===
CPU_AVG
CPU_AVG_1M
CPU_AVG_5M
CPU_AVG_15M
SSH_USERS_CONNECTED
UPTIME