Changed the index type to a string everywhere.

Changed the index type to a string everywhere.

The functions zebra_map_get and zebra_map_get_or_add changed their
3rd argument 'int reg_id' to 'const char *id'. The recExtractCtrl struct
defined in idzebra/recctrl.h changed: the seqno array was removed. It
is used by no filters and assumes that index type(AKA register type)
is a char (int).