S1: Some label on ASCII dialog were changed:
1. Show blue hint "each character is treated as one delimiter" when the number of "Other Delimiters” is more than 1.
2. Multiple Delimiters --> Multiple Characters
3. Combine Delimiters as one Delimiter --> Treat Consecutive Delimiters as One (use a same label as ImpWiz)
4. Move "Header Lines" branch node above "File Structure" node, to be consistent with ImpWiz.

S2: Restrict editbox to allow single character input

On Import Wizard dialog, Data Columns page, the "Other" editbox is not allowed to enter more than 1 char.