Do we simplify cfg [Machine]bmp_names

[Christian-B]

The cfg setting bmp_names allows for a lot of complexity but much of it appears never used.

format is:
bmp_names = <bmp_id>[:<bmp_id>]*
<bmp_id> = [[<cabinet_id>;]<frame_id>;][/(|board_id[,board_id]*)]
<board_range> = <board_id>-<board_id>
where:
<cabinet_id> is the ID of a cabinet
<frame_id> is the ID of a frame in a cabinet
is the hostname or IP address of the BMP
<board_range> is a range of boards that the BMP can speak to
<board_id> is the ID of a single board in a frame
ref:

SpiNNMan/spinnman/spinnman.cfg

Line 15 in 5d3ddea

# format is:

However
bmp_names is not the template cfg nor mentioned in the github.io pages so unlikely to be used by many users
only uses we have are
machineName = spinn-4.cs.man.ac.uk
bmp_names = spinn-4c.cs.man.ac.uk

This results in BMPConnectionData having many Values that are rarely anything but the defaults
including cabinet, frame, boards and port_num

Which in turn complicates Transceiver methods such as:
check_bmp_connections
power_on_machine
power_off_machine

[Christian-B]

@rowleya suggested "Yes, just having an IP address and possibly a list of board ids should be plenty from what I can see"

[Christian-B]

Suggest leaving as is until spin2 full implemented and the review