Improved and simplified Ping

[s-hadinger]

Description:

I was not happy with the first implementation of Ping.

This new implementation supports multiple pings ongoing at the same time, is reduced from 3KB to 2KB, and supports a new 'fast mode' when you're only interested in reachability.

Fast mode: Ping0 <addr> will send at most 4 pings, and will report immediately once a succesful response is received. You can batch pings with BackLog.

Ex:

Backlog Ping0 192.168.1.203; Ping0 192.168.1.205; Ping0 192.168.1.207; Ping0 192.168.1.208; Ping0 192.168.1.222

17:57:47 CMD: Backlog Ping0 192.168.1.203; Ping0 192.168.1.205; Ping0 192.168.1.207; Ping0 192.168.1.208; Ping0 192.168.1.222
17:57:47 RSL: stat/tasmota_4B3316/RESULT = {"Ping":"Done"}
17:57:47 RSL: tele/tasmota_4B3316/RESULT = {"Ping":{"192.168.1.203":{"Reachable":true,"Success":1,"Timeout":0,"MinTime":86,"MaxTime":86,"AvgTime":86}}}
17:57:47 RSL: stat/tasmota_4B3316/RESULT = {"Ping":"Done"}
17:57:48 RSL: tele/tasmota_4B3316/RESULT = {"Ping":{"192.168.1.205":{"Reachable":true,"Success":1,"Timeout":0,"MinTime":170,"MaxTime":170,"AvgTime":170}}}
17:57:48 RSL: stat/tasmota_4B3316/RESULT = {"Ping":"Done"}
17:57:48 RSL: stat/tasmota_4B3316/RESULT = {"Ping":"Done"}
17:57:48 RSL: tele/tasmota_4B3316/RESULT = {"Ping":{"192.168.1.207":{"Reachable":true,"Success":1,"Timeout":0,"MinTime":104,"MaxTime":104,"AvgTime":104}}}
17:57:48 RSL: stat/tasmota_4B3316/RESULT = {"Ping":"Done"}
17:57:48 RSL: tele/tasmota_4B3316/RESULT = {"Ping":{"192.168.1.208":{"Reachable":true,"Success":1,"Timeout":0,"MinTime":82,"MaxTime":82,"AvgTime":82}}}
17:57:52 RSL: tele/tasmota_4B3316/RESULT = {"Ping":{"192.168.1.222":{"Reachable":false,"Success":0,"Timeout":4,"MinTime":0,"MaxTime":0,"AvgTime":0}}}

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on core Tasmota_core_stage
• The code change pass travis tests. Your PR cannot be merged unless tests pass
• I accept the CLA.

[MarkCiliaVincenti]

Works for me :)