Replace embedded OSGi-prefs sources by bundles from Maven-Central (#39)

And update to latest version of
- org.osgi.service.prefs

This is part of issue:
https://github.com/eclipse-equinox/equinox.framework/issues/40

bundles/org.eclipse.equinox.preferences/META-INF/MANIFEST.MF

@@ -7,11 +7,11 @@ Bundle-Activator: org.eclipse.core.internal.preferences.Activator
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
 Require-Bundle: org.eclipse.equinox.common;bundle-version="[3.2.0,4.0.0)",
- org.eclipse.equinox.registry;bundle-version="[3.2.0,4.0.0)";resolution:=optional
+ org.eclipse.equinox.registry;bundle-version="[3.2.0,4.0.0)";resolution:=optional,
+ org.osgi.service.prefs;bundle-version="[1.1.0,1.2.0)";visibility:=reexport
 Export-Package: org.eclipse.core.internal.preferences;x-friends:="org.eclipse.core.resources,org.eclipse.core.runtime,org.eclipse.equinox.p2.engine",
  org.eclipse.core.internal.preferences.exchange;x-friends:="org.eclipse.core.runtime",
- org.eclipse.core.runtime.preferences;version="3.5.0",
- org.osgi.service.prefs;version="1.1.1"
+ org.eclipse.core.runtime.preferences;version="3.5.0"
 Bundle-ActivationPolicy: lazy; exclude:="org.eclipse.core.internal.preferences.exchange"
 Import-Package: org.eclipse.osgi.framework.log,
  org.eclipse.osgi.service.datalocation,
@@ -20,7 +20,6 @@ Import-Package: org.eclipse.osgi.framework.log,
  org.eclipse.osgi.util,
  org.osgi.framework,
  org.osgi.service.packageadmin,
- org.osgi.util.tracker,
- org.osgi.service.prefs;version="[1.1.1,1.2)"
+ org.osgi.util.tracker
 Bundle-RequiredExecutionEnvironment: JavaSE-11
 Automatic-Module-Name: org.eclipse.equinox.preferences