ec_pdo_t and ec_pdo_entry_t classes, added fmmu_config_t, adjusted
minimal example, etc...

improved SII code.

ec_master_sync_io(); introduced events in the master state machine;
locking of slave scanning and slave configuration through allow_scan
and allow_config flags.

ec_master_calc_addressing(), coupler_index and coupler_subindex variables.
Adapted lsec script and examples.

registration functions now take a slave pointer as argument; changed
values for ec_bus_status_t.

master array; hand ober MAC addresses with array module parameters.