adjust sql statements to work properly with oracle database

OF-1212 adjust ddl statements for oracle

add possibility to store complete stanza in archive

This change ensures that messages are received in the order that they were originally sent to the user that was unavailable/offline.

in the settings there is now a switch allowing to add complete stanza to
the archive for muc conversations

as oracle database cannot use distinct modifier on clob columns some
statments must be adjusted so they don not fail on oracle database

since two long columns are not permitted in one table by oracle and the
datatype long is deprecated, the respective columns are changed to clob

This performs the same fix as for PEP, but this time on the PubSub services.

The PEP Service configures leaf nodes to store -1 items by default; however
this value is not corrected by the usual post-configuration checks to 1, and
this in turn means that when gathering the items to return, the single
item is removed.

This patch corrects the issue by setting the maxPublishedItems in the default
configuration to 1 instead.

IQ requests must always be responded to, if only with an error reply. For good
measure, IQ-Ping support was added too.

Simply repeated dwd's commit 73b59106 on Ubuntu Trusty (20160104ubuntu0.14.04.1)

OF-1116: Apply workaround for Java 7/8 compatibility issue

The JDK 7 signature of ConcurrentHashMap#keySet() returns a Set, while JDK 8 signature
returns a KeySetView, which is a new class in JDK 8. As a result, using Java 7 to run
an Openfire instance that is compiled with Java 8 (using the -source/-target 1.7
compilation flags) causes a java.lang.NoSuchMethodError.

To work around this problem, this commit applies a workaround as presented by
Martin Buchholz in https://bugs.openjdk.java.net/browse/JDK-8151366

alter statements (at least in oracle 11g or earlier) do not allow the
COLUMN keyword after ADD in an ALTER statement
Conflicts:
	src/database/upgrade/23/openfire_oracle.sql

OF-1157

Will build on bamboo + debian with java7 as well

Conflicts:
	build/debian/rules

 * will maintain this on the ignite bamboo server as a symlink

The abstract implementation of GroupProvider should not hide the thrown
clause as defined by the createGroup() signature.

When validating a certificate chain, the provided chain aught to be ordered. If our
own ordering fails, we should use the first certifcate of the (unordered) chain,
instead of failing completely.