releng, Bug 580920: Replace Java 1.8 w/ version 11Replace version 1.8 with 11 in all .classpath, .settings and manifestfiles across every Eclipse project. Also update [1] as applicable too:[1]skeleton/skeleton.rcp/skeleton.tracecompass.parent/pom.xmlJava 11 is the current minimum version required by Eclipse [2], runtimewise. Make 11 also the base at language level. This change depends onthe core one [3].[2]https://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM[3]https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/196306Change-Id: Ife6f51999ebe1cf240137a7628f2f3ee96fdeb6dSigned-off-by: Marco Miller <marco.miller@ericsson.com>Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/196309Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>Tested-by: Patrick Tasse <patrick.tasse@gmail.com>Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>