Fixed parsing issue  for MySQL where strings ending in a [space]x|b'

Fixed parsing issue  for MySQL where strings ending in a [space]x|b' were not being terminated properly by the MySQLSqlStatementBuilder (see issue #593). Checked to see if token's length was greater than 2. Any bit or hex literal should at the minimum have a length of three (i.e. b'' or x'') but the case where a string ends with a [space]x|b' (i.e. ' x') then the length is only two. This seemed like the easiest way to determine if the token was truly a bit/hex literal or the ending sequence of a string. I also added two tests to test for the [space]x|b' case being improperly terminated.