Combined basic_string.h, ibasic_string.h & string_base.h. Deleted ibasic_string.h & string_base.h
Combined basic_string.h, ibasic_string.h & string_base.h.
Deleted ibasic_string.h & string_base.h

ETLCPP/etl,ETLCPP/etl,ETLCPP/etl,ETLCPP/etl