527683: Update required Java version to 1.8

Fixed BREE and java version in parent pom

Bug: 527683
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=527683

org.eclipse.epp.mpc-parent/pom.xml

@@ -15,7 +15,8 @@
    <properties>
       <mpc-version>${project.version}</mpc-version>
       <target-platform>staging</target-platform>
-      <java-version>1.5</java-version>
+      <java-version>1.8</java-version>
+      <java-bree>JavaSE-${java-version}</java-bree>
       <!-- We need at least 1.8.0 to run the build, even though we're still building with 1.5 source level. 
            Otherwise some plugin downloads won't work and the test runtime can't start -->
       <enforced.java.version>[1.8.0,)</enforced.java.version>
@@ -205,7 +206,7 @@
                <version>${tycho-version}</version>
                <configuration>
                   <resolver>p2</resolver>
-                  <executionEnvironmentDefault>J2SE-${java-version}</executionEnvironmentDefault>
+                  <executionEnvironmentDefault>${java-bree}</executionEnvironmentDefault>
                   <includePackedArtifacts>false</includePackedArtifacts>
                   <ignoreTychoRepositories>true</ignoreTychoRepositories>
                   <target>