prepare for next development iteration (3.2.1)
backport: fix postgres validation query (MARMOTTA-498)

(cherry picked from commit dfde1a8ea61dbbd43318af63b7278d42beddc38d)
Signed-off-by: Jakob Frank <jakob@apache.org>
[maven-release-plugin] prepare release 3.2.1
Merge master into develop
Merge remote-tracking branch 'origin/develop' into develop
Add an LDPath function (fn:header) to retrieve a backend-defined
response header for a resource

The AbstractHttpProvider provides an example implementation that stores
all the HTTP headers. Other backends have empty header implementation.
SPARQL: fix bug in DISTINCT in combination with UNION
MARMOTTA-489, MARMOTTA-490: Improved Test-Logging for the KiWiDatabaseRunner
Somehow this DISCLAIMER.txt is hard to get rid of...
MARMOTTA-485: moved LinkedData CLI into a separate module that is not deployed/installed to the maven repo
(but contains the CLI bundle)
MARMOTTA-485: Updated release process to use the new ldpath-ldquery package
fixed possible NPE when running ldpath-templating from CLI
add JSON output format for LDQuery CLI tool
Add fn:jsonpath to evaluate a JSONPath expression on a value

JSONPath: https://github.com/jayway/JsonPath
Add "x within y" node selector for working with HTTP RDF sources with
inlined resources

Remote RDF resources sometimes contain additional RDF resources besides
the request URI. When these inlined resources are requested (using x
within y), mint a temporary identifier for the resource in the ldcache
and allow it to be used by downstream selectors as if it were a
full-fledged web resource.
Smuggle the original resource URI using a namespace prefix/name pair.
Allow 'x within y' selector to also work with blank nodes returned by resources
Merge branch 'ldpath-json' into spotlight-integration

* ldpath-json:
  add JSON output format for LDQuery CLI tool
Merge branch 'ldpath-json-functions' into spotlight-integration

* ldpath-json-functions:
  Add fn:jsonpath to evaluate a JSONPath expression on a value
Merge branch 'ldcache-headers' into spotlight-integration

* ldcache-headers:
  Add an LDPath function (fn:header) to retrieve a backend-defined response header for a resource

Conflicts:
	libraries/ldcache/ldcache-core/src/main/java/org/apache/marmotta/ldcache/services/LDCache.java
	libraries/ldpath/ldpath-api/src/main/java/org/apache/marmotta/ldpath/api/backend/RDFBackend.java
	libraries/ldpath/ldpath-backend-jena/src/main/java/org/apache/marmotta/ldpath/backend/jena/GenericJenaBackend.java
	libraries/ldpath/ldpath-backend-linkeddata/src/main/java/org/apache/marmotta/ldpath/backend/linkeddata/LDCacheBackend.java