First draft of sample widgets

Jira issue: wp-580
Updated readme files

Jira issue: wp-580
More updates to readme.md

Jira issue: wp-580
Folders refactoring for Arduino platform

Jira issue: WP-595
Implemented functionality for reading configuration parameters from SD
card in Arduino MEGA board

Jira issue: WP-595
Implemented dynamic IP assignment (DHCP) in HTTP driver for Arduino Mega board

Jira issue: WP-595
Fixed connection bug in sendDataToAPI method.

Jira issue: WP-595
Made MAC address configurable from SD card for Arduino MEGA Board

Jira issue: WP-595
Merge pull request #398 from glatorre/WP-595

Implemented DHCP and SD card functionalities for Arduino Mega platform (WP-595)
Merge pull request #402 from TobyEalden/wp-580

Create an example widget and signature guide
Merge branch 'master' of https://github.com/webinos/Webinos-Platform