core: Re-connect for ECONNRESET or ECONNABORTED

core: Re-connect for ECONNRESET or ECONNABORTED

This patch keeps scanning and re-connections active if the disconnection
reason is ECONNRESET(Remote Initiated Disconnection).

Re-connection is a behaviour determined by Profiles or by the upper
layer(user actions). For instance, HoG requires re-connection always
active, no matter if the previous disconnection reason was page timeout
or remote initiated disconnection (ECONNRESET). Some devices disconnects
after some idle time, connectable advertises are sent by the peripheral
when commanded by the user(eg: key pressed). Disconnection can be also
triggered by the local host (ECONNABORTED) using command line tools or
Disconnect method in the Device interface.

The peripheral dictates the re-connection controlling the connectable
advertises, BlueZ(central) needs to keep the scanning always active to
able to detect the advertises and trigger the connection.