Components and maven plugins upgrades

Components upgrades:
* Jaxen 1.1.1 -> 1.1.6
* Commons-io 2.1 -> 2.4

Test components upgrades:
* Junit 4.10 -> 4.12 (fix some deprecated)
* Betamax 1.0 -> 1.1.2 (changind groupdId and imports to co.freeside)
* Groovy 1.8.4 -> 2.3.8 (used by betamax)

Plugins upgrades:
* site 3.0 -> 3.4 (Needs Doxia v1.6)
* assembly 2.2.2 -> 2.5.2
* clean 2.4.1 -> 2.6.1
* compiler 2.3.2 -> 3.2
* checkstyle 2.8 -> 2.13 (and activate report)
* findbugs 2.3.2 -> 3.0.0
* javadoc 2.8 -> 2.10.1
* source 2.1.2 -> 2.4
* surefire 2.10 -> 2.18
* PMD 2.6 -> 3.3
* dependency 2.3 -> 2.9
* deploy 2.7 -> 2.8.2
* eclipse 2.8 -> 2.9
* enforcer 1.0.1 -> 1.3.1
* GNUpg 1.4 -> 1.5
* helper 2.1.1 -> 2.2
* install 2.3.1 -> 2.5.2
* jar 2.3.2 -> 2.5
* release 2.2.1 -> 2.5.1
* resources 2.5 -> 2.7

Misc:
* Externalization of versions as properties in pom.xml
* Ignore dom4j strange version in version report

Local unit tests OK and generated client tests on rundeck monitor OK