1. Eliminate possibility to call __*collate_range_cmp() with inclomplete

locale (which cause core dump) by removing whole 'table' argument
by which it passed.

2. Restore collate_range_cmp() in sccl().

3. Collating [a-z] range in regcomp() only for single bytes locales

(we can't do it now for other ones). In previous state only first 256
wchars are considered and all others are just silently dropped from the
range.