Add Java 8 connector (JDT/WTP/M2E) in Central for JBT 4.1.2

We decided to provide an easy way for JBT users to install Java 8 support in Eclipse Kepler SR2 in 1 click, instead of have to chase the update sites for JDT, M2e and WTP.

• JDT Feature patch : http://download.eclipse.org/eclipse/updates/4.3-P-builds/
• M2E 1.4.1 (org.eclipse.m2e.feature) http://download.eclipse.org/technology/m2e/releases/1.4/1.4.1.20140328-1905
• WTP Feature Patch : http://download.eclipse.org/webtools/patches/drops/R3.5.2/P-3.5.2-20140329045715/repository

All 3 features should be available via a unique connector in JBoss Central > Software Updates