Update build to use Tycho 0.18
Update build to use Tycho 0.18

Change-Id: I4033051e9ffd22b7f6d4b144b4ea85a11037eada
Signed-off-by: Matthias Sohn <446760a3fbea85cd5f8f4f5c3de304fe3a38014f@sap.com>

wdliu/egit,paulvi/egit,collaborative-modeling/egit,SmithAndr/egit,wdliu/egit,collaborative-modeling/egit,paulvi/egit,blizzy78/egit,SmithAndr/egit