Updated common and communication libs - make OTA Update more reliable
Merge branch 'master' into bug-fixes
Spark_Save_Firmware_Chunk() now returns next_chunk_index instead of bool
Ping
Clear Wi-Fi creds should behave like factory reset

See issue #128 and the fix by @davids5 and @satishgn in commit
a5ae9f420b on Feb 25. Apply same fix to normal clearing of Wi-Fi
credentials. This fixes a bug where clearing credentials by holding the
MODE button for 10 seconds, then resetting the Core, would result in
flashing green instead of the expected flashing blue.
Merge pull request #173 from spark/clear-wifi-creds-fix

Clear Wi-Fi creds should behave like factory reset
Merge pull request #155 from spark/bug-fixes

Updated common and communication libs - make OTA Update more reliable (should help #124)
Merge pull request #156 from bkobkobko/NetworkPing

Add Support for Network.ping()
v0.2.1 binaries
Merge branch 'master' into feature/flash-eeprom-emulation
Removed conditional compilation blocks and added citation