pgsql: Allow \timing in psql to have a better resolution than ~15ms on

Log Message:
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Allow \timing in psql to have a better resolution than ~15ms on Windows.

ITAGAKI Takahiro

Modified Files:
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pgsql/src/bin/psql:
common.h (r1.54 -> r1.55)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/common.h.diff?r1=1.54&r2=1.55)