[Xastir] Xastir on the Raspberry Pi

[Max Harper]

Hello to everyone in the group. The name here is Max KG4PID and I'm new to Linux and  Xistir. I also have a Raspberry Pi
 running APRX as an Igate using a TNC-Pi. I have played with APRS for about 8 years and know which end of a soldering iron
 gets hot. I am not a programmer but I have done a few things in Basic and Pic ASM and know neworking basics. 
 
I installed Xastir on my Raspberry Pi using "sudo apt-get install xastir". Help-About shows Version 2.0.0 Compiled Jul 29 2012.
 While I'm not sure what the latest version is, looking back through the archives I did see mention of version 2.0.2 released a
 year ago. Why doesn't apt-get install the latest version? I was hoping to be able to see the wearther watches / warnings but in
 the archives there was talk of having to get the latest version for this to work, and having to regularly do this because the
 NWS keeps changing things or something to that effect. Are their any instructions for someone like myself that will get the
 latest version and get everything up and running? 
 
I have also been reading a little about AX.25 and at some point I think I would like to have Xastir and APRX both running using AX.25. It's my understanding that AX.25 makes the connection to the APRS-IS and the two applications would use that connection, correct? Or is AX.25 only for the TNC to be shared and each application still makes its own connection to the
 APRS-IS?  Do packets also get passed between the two applications ? What about when one application sends a packet to
 the TNC, does it also come back in to the other application? I'm trying to get the big picture here as to how all this works
 together. 
 
Thanks for reading and your patience. Max