updateros: remove unused encap parsing code.
updateros: change netmask to maskLength.
Add version check.

Check the API version before every call so we don't break something if a
backward-incompatible change is introduced.
Rewrite updateros.py to use EncapEntry objects instead of (dstaddress, gateway) tuples.
Merge branch 'master' of https://github.com/kd7lxl/python-amprapi into kd7lxl-master

Conflicts:
	updateros.py
Merge branch 'kd7lxl-master'