issue-641 Trivial improvements to *pom.xml

Hi dev@hector
I quickly created the issue-641 branch for this issue.
This pull request 
* updates pom.xml's to use project.version as oppose to pom.version (the latter being deprecated)
* make better use of the <properties> child element for storing and specifying plugin versioning and dependency versioning
* cleans up code formatting in parent pom.xml
* removes duplicate maven-jar-plugin configuration and the comment which accompanied this plugin config.
Thanks