[DRAFT] Tycho build for orion.server

seems to work:
- build bundles and features
- assembly of p2 repository and product zip
TODOs:
- tests fail
- server doesn't yet start (Application
"org.eclipse.orion.server.ui.consoleApp" could not be found in the
registry. The applications available are: org.eclipse.equinox.app.error,
org.eclipse.help.base.infocenterApplication,
org.eclipse.help.base.helpApplication, org.eclipse.help.base.indexTool,
org.eclipse.orion.application)
- some build.properties had to be tweaked, check if this is ok
- license feature was commented out
- check target platform for correctness
- check if result matches PDE build result
- root files ?
...

Bug: 399023
Change-Id: I1ffa9c6795bab8656ad7c9e949dc38d18a74e613
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>