improve multiple results support
The specification talks exactly about -1:
> Returns: the current result as an update count;
> -1 if the current result is a ResultSet object or there are no more results
Other negative numbers can theoretically mean something different than „no more results“
e.g. unknown number of updates (?).
#Fri Jan 05 23:50:28 CET 2018
project.licensePath=./nbproject/licenseheader.txt