Distribution repositories have been added to the POM file so that the
project can be deployed in the SING's Maven repository.

The QUAL column may have a dot (.) value when its value is unknown. The
current code was treating this column as a double value in all cases, so
that it failed when the value was unknown.

This commit adds support for unknown values in QUAL column, such that
these values are converted into NaN values.

Also added try-with-resources block to close input stream