LP#1687649 Z39.50 CQL query parser honors bools

LP#1687649 Z39.50 CQL query parser honors bools

To test with yaz-client, Z server on localhost, database=evergreen:

Z> open localhost:2210/evergreen
Z> find @or @attr 1=4 @attr 4=6 "potter" @attr 1=4 @attr 4=6 "piano"

"Number of hits:" value should be greater than zero (~38) using the
concerto data set.

Similarly, opensrf logs should contain the line:

SRU search string [(title = potter or title = piano)] converted to
[title:potter || title:piano]

Signed-off-by: Bill Erickson <berickxx@gmail.com>