Added node enabled/disabled flag https://xeolabs.lighthouseapp.com/projects/50643-scenejs/tickets/169-enabledisable-flag-for-nodes#ticket-169-2
Added node enabled/disabled flag
https://xeolabs.lighthouseapp.com/projects/50643-scenejs/tickets/169-enabledisable-flag-for-nodes#ticket-169-2

tsherif/scenejs,dayo7116/scenejs,dayo7116/scenejs,tsherif/scenejs