Changes

releng, Bug 580920: Replace Java 1.8 w/ version 11

Replace version 1.8 with 11 in all .classpath, .settings and manifest
files across every Eclipse project. Also update [1] as applicable too:

[1]skeleton/skeleton.rcp/skeleton.tracecompass.parent/pom.xml

Java 11 is the current minimum version required by Eclipse [2], runtime
wise. Make 11 also the base at language level. This change depends on
the core one [3].

[2]https://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM
[3]https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/196306

Change-Id: Ife6f51999ebe1cf240137a7628f2f3ee96fdeb6d
Signed-off-by: Marco Miller <marco.miller@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/196309
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>