Remove OBJ_bsearch_() usage from PBE

Remove OBJ_bsearch_() usage from PBE

Split the table of built-in password based encryption algorithms into two
and use a linear scan over the table corresponding to the type specified
in EVP_PBE_find()'s type argument. Use better variable names, make the
API a bit safer and generally reduce the eye bleed in here.

ok jsing