Added basic support for the Philips Hue lights.

This is a first commit adding basic on/off support.
Insteon::DimmableLight Fix convert_level to return FF for 100%

100% was being converted to FE when it should be FF.

Fixes Issue #147
Insteon_PLM Fix So Callback is Used if NAK Received on Manage AllLink

This will allow sync_links and delete_links to continue if a NAK received from the PLM.

Fixes Issue #148
Functionality and doc update

Added effect support and updated the documentation so that it follows
the requires format.
Added functionality to control the color and the brightness of a lamp
Added function to control hue, saturation and brightness in one command
Merge pull request #149 from krkeegan/fix_issue_147

Insteon::DimmableLight Fix convert_level to return FF for 100%
Merge pull request #150 from krkeegan/fix_issue_148

Insteon_PLM Fix So Callback is Used if NAK Received on Manage AllLink
Merge pull request #131 from hollie/add_philips_hue_support

Adding support for the Philips Hue light system