Fixed Memory Leak

Bugfix for memory leak when disconnecting.

2.2.0

• Updated Documentation
• Updated examples
• Added support for cellular
  • replaced deprecated getmacaddress with logic to retrieve wifi mac from imp.net.info or the device id (addresses issue: #15)
• Updated check for imp005 to use imp.info()
• Updated onReady method
  • Will always store onReady callback
  • Will always check for updated network settings to apply before triggering user's callback

2.1.1

• Fixed a typo that leads to a runtime issue.

2.1.0

• Introduced setMac, which specifies whether the library should set the MAC address of the chip to the imp's MAC.

2.0.0

A few minor issues fixed:

• Proper units for setRetries timeout;
• Acceptance confirmation for socket commands;
• Copyrights updated;

Renaming:

• W5500.device.nut -> W5500.device.lib.nut;
• W5500.DHCP.device.nut -> W5500.DHCP.device.lib.nut.

1.0.0

Wiznet 5500 libraries.