Update parent POM configuration to latest plugin versions

* set property `project.reporting.outputEncoding` to "UTF-8"
* maven-compiler-plugin:3.1
    * set Java source and target to 1.7
* maven-dependency-plugin:2.8
* maven-enforcer-plugin:1.3.1
    * require Maven 3.1.1
    * require Java 1.7.0
* maven-install-plugin:2.5.1
* maven-javadoc-plugin:2.9.1
* maven-project-info-reports-plugin:2.7
* maven-release-plugin:2.4.2
    * Update SCM dependencies to 1.8.1 to address incompatibility to Git 1.8.5
* maven-site-plugin:3.3
* maven-surefire-plugin:2.16
[maven-release-plugin] prepare release pcm-parent-2