Update setColonOnOff, setDecimalOnOff

Updated functions to return a bool value. Also fixed some syntax errors in library.properties and keywords.txt.

Support for "calloc" function

Updated library so that "calloc" function works on different processors and not just ATMega328p.

User defined character

Added function and example for the user to define their own characters.

Superficial changes to library

No changes to how the library or examples function, but added links to get the library and buy boards from SparkFun to the examples. Updated readme.

Initial release

v1.0.0

Updated library.properties and keywords.txt