Issues with APRS filtering

[matburnham]

A number of issues manifest when attempting to use the APRS filter option. These issues are not necessarily that apparent when using a full feed.

• Curt error message: socket.error #113
• Socket errors with too little traffic #114
• No APRS passcode support for APRS write-access #115

[acasadoalonso]

We need further documentation of the issue.