Android PFD and SystemAlarms: Ensure that objectUpdated is not called for a null object

Both SystemAlarms and PFD (fragments) are getting a connected signal and then not finding
objects that should exist (SystemAlarms and AttitudeActual respectively).  This is probably
when connected to an unknown UAV type and should be handled gracefully like now.
However, it would be good to confirm this doesn't happen when connected to a known
UAVO set.

fixes #203
Windows Packaging: Including libstdc++-6.dll

I'm not sure why this wasn't required previously or causing
other issues but including it resolved an issue for Al.
Linux Packaging: Don't use sudo for postinst

Since the whole packaging installation runs as root
calling sudo is unnecessary.
Merge pull request #204 from PhoenixPilot/james/windows_libstdc++

Windows Packaging: Including libstdc++-6.dll