add narrow-query OR(|) expression

[t9md]

#174
Experimentally add | as OR expression for narrow-query.

• wordA|wordB matches items include wordA or wordB.
• Can chain multiple OR, a|b|c matches items for a or b or c.
• query a|b|c d means, matches items (a or b or c) and also maches d.
  • General rule: | is treated as OR, white-space is always treated as AND.
• This OR handling is NOT happen when query word starts or ends with | char.
  • e.g. |a, a|, |a|b , a|b|, |a|b|, all searched as-is(literally), | is not evaluated as OR.