#115 SetPortOpts overwrites port settings

[Barry Andrews]

The setportOpts function only allows for a pager service with 7 data bits, even parity and 1 stop bit.
There are some paging services which require 8 data bits no parity and 1 stop bit.
Calling SetPortOpts in the DoOpenPort function means that any existing port options are always overwritten, even if you wish to use the different settings.