Implemented tests for BWT
A skeleton for SACA is implemented.
SACA - put_str0, induce_l0, induce_s0, type conversion is improved
SACA - implemented the rest of level[0] routines, not operational yet.
Refined 0-level induction, added 1 to intermediate suffixes, fixed to produce valid semi-sorted LMS.
SACA - achieved proper level-0 processing