We had an upgrade issue where using newer firmware with older
osmo-bts binaries didn't work. Make sure that the shiny new 0.4.0
binaries are used with firmware starting from 3.2.
Addresses: #158
The build differs in that it doesn't use a getty on ttyS0. In the fuutre,
a modified kernel serial driver as well as a 2050-specific utility
for managing the supervisor processor will follow.