Set M2_Home for maven builds and add maven to the path so if the build
needs to run maven from maven (or maven from ant from maven) it can.

Conflicts:
	maven-plugin/pom.xml
	plugins/pom.xml
	ui-samples-plugin/pom.xml

Otherwise plugin classes won't resolve.

${param}

param = http://host/job/foo/14



If you just wanted the name ('foo') or the number (14) as an expansion,
you're forced to re-tokenise it somehwere else such as a script.

Add 2 extra environment vars:
param.jobName = foo
param.number  = 14

Signed-off-by: Nigel Magnay <nigel.magnay@gmail.com>

effectively bumping maven-release-plugin from 2.0-beta-9 to 2.1,
and maven-javadoc-plugin from 2.2 to 2.7 (there was a comment
here that 2.3 caused some release problem so sticking with 2.2..
hopefully 2.7 will be ok)

(effectively bumping from 1.63 to 1.64)

Updating to use parent POM 1.14 (with hardcoding of maven-hpi-plugin 1.64) and to explicitly use maven-hpi-plugin 1.64, to fix requiredCore missing problem with plugins.

[JENKINS-8711] Post build action deploy to maven repository can fail using "private maven repository" option