This adds in-place patching of the time information in the
MM INFORMATION message. The timezone in the 'Local time zone' and
the 'Universal time and local time zone' information elements
and the offset in the 'Network Daylight Saving Time' information
element are optionally set.
The new values are determined by the 'timezone' vty command in the
config_net_bts node. That command is extended by an optional
DST offset parameter.
Tests are provided for the vty part and for the plain
Sponsored-by: On-Waves ehf