Added function Adafruit_7segment::writeColon() - write the buffered colon value to the display without having to write the full display buffer
Correct HT16K33_CMD_BRIGHTNESS value and usage
Merge commit '6cb1c3588adf707d38c006e7ccabcc9291c6093a'
Merge branch 'master' of https://github.com/adafruit/Adafruit-LED-Backpack-Library

# By ladyada
# Via ladyada
* 'master' of https://github.com/adafruit/Adafruit-LED-Backpack-Library:
  bicolor bargraph
  Support for 24-bargraph
Merge pull request #8 from djix123/master

Added function Adafruit_7segment::writeColon() - write the buffered colo...