Changes

Fix for bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=534087
Allow ECF to build against both R6 and R7 implementations of the 
org.osgi.service.log API. This is accomplished by providing stubs of the
new interfaces on the build-time classpath so that we can implement the
new R7 methods without having unresolved classes on R6.
The stubs are not shipped with the binary distribution of ECF, so in the
actual ECF code we can use them as long as we avoid any explicit import
statements to avoid runtime linkage errors on R6.
Change-Id: Ib29135c030e3dd8a3bf799552a2f3144c26edfe3 Signed-off-by: Mat
Booth <mat.booth@redhat.com>