comp: create pcl.framework for pcl-ios-device only

Since the iOS simulator build doesn't work out-of-the-box, it is disabled
by default, but we still want to create the pcl.framework.  So for now,
build the framework without the ios-simulator objects.
comp: the latest version of ves superbuild requires a new configure option

In the latest version of VES, you must pass VES_NO_SUPERBUILD when
configuring VES, otherwise it will trigger its own superbuild, which
we don't want for pcl-superbuild.
comp: use sha1 identifiers instead of branch names

This avoids the superbuild pulling new, untested commits when the
branches are updated.  Now the superbuild uses fixed sha1 ids when
checking out vtk and ves repositories.