Detect if dkpg / arp-scan has errors or can't be run on bridge initialization

[davafons]

Expected Behavior

When a connection to the bridge computer is made, the status of dpkg and arp-get commands should be checked, to assert that programs can be installed.

For example, in cases like dpkg Error code 100, which requires to run sudo dpkg --configure -a before continuing.

Actual Behavior

If dpkg or arp-get is in an error status, the _bridge_initialization plugin won't be executed correctly, and won't install any dependencies.

Steps to Reproduce the Problem

Hard to reproduce.