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 (?).

sqldk-relpipe convergence: integer type (relpipe already support signed integers)

fix license version: GNU GPLv3

change XMLNS for the configuration
Use The 'tag' URI Scheme <http://www.faqs.org/rfcs/rfc4151.html>
Upgrade local configuration:
sed 's@https://sql-dk.globalcode.info/xmlns/configuration@tag:globalcode.info,2018:sqldk/configuration@g' -i ~/.sql-dk/config.xml

transform the record formatter into the recfile formatter
still a human-readable format and very similar
but also machine-readable – can be processed in GNU Recutils and Relational pipes

getTableName() is needed for the metadata

support custom relation names in the XML formatter (added --relation CLI option)

sqldk-relpipe convergence started

back to the snapshot

Added tag v0.10 for changeset 0503996934e0

release: 0.10

switch to JUnit5

mavenized: sql-dk-parent

mavenized: jdbc-dk-driver

mavenized: sql-dk

mavenized: jdbc-loopback-driver

Avoid reusing/rewriting the DB connection properties.
There was weird random errors while testing connection to multiple DB in parallel when one of them was meta connection to same DB connection.
Two kinds of exception: 1) missing password 2) „Passing DB password as CLI parameter is insecure!“

JDBC drivers: fix 'Unsupported URL' – drivers might be called witrh wrong URLs and then they should (according to the JavaDoc) return null instead of throwing an exception.
This problem occurred when --test-connection was testing multiple connections in parallel.

TabularFormatter: add support for SQLXML values

XML array hack

c++: recognize batch mode

netbeans

c++ version skeleton

InfoLister/test: show also database server name and version

BarChartFormatter: TODO comments

headerTypes: new option to hide column types in tabular headers

BarChartFormatter: format null as an empty/missing bar + better logging

XmlFormatter: support for printing SQLXML types

BarChartFormatter: first version

LoggerProducer

bash_completion.pl: defaultFormatter

bash-completion: --formatter-property choices: first working version

bash-completion: --formatter-property names

SingleRecordFormatter: escape whitespace characters in the same way as in TabularFormatter (fixed)

SingleRecordFormatter: escape whitespace characters in the same way as in TabularFormatter

--list-formatter-properties: better help/description

--list-formatter-properties: optional column declared_in

Usage:
sql-dk --list-formatter-properties tabular --list-formatter-properties xml --list-formatter-properties xhtml --list-formatter-properties tex --formatter xhtml --formatter-property InfoLister:print:declared_in true > formatter-properties.xhtml

--list-formatter-properties: added column declared_in

property annotations: first woking version of --list-formatter-properties

getClassHierarchy function

property annotations: first version (inherited properties are not working yet)

property annotations: dummy InfoLister table

InfoLister: private methods + formatter for formatter properties

property annotations: grounds for --list-formatter-properties

Java 8 for jdbc-dk-driver

property annotations: default values

property annotations (documentation) for particular formatters

property annotations for documentation of formatter properties