Wifi fix

Better way to check for wifi nodes using bl_idname, which cannot be
change by user unlike the node name
Merge pull request #29 from nortikin/master

sync line connect, fix series
free in ViewerDraw

Turns off drawing when node is deleted
Update util.py
another wifi name fix
socket_id fix

socket.name is not guaranteed to be unique but socket.identifier is. fixes a potential bug if many output sockets has the same name. right now this is not the case in sverchok and
SvSetSocketAnyType works because of this but is potentially flawed.
Merge pull request #43 from ly29/master

proper check for wifi nodes