Progress on Exodus-II bridge.
Progress on the Exodus-II bridge.

It compiles but this Python script:

    import smtk
    mgr = smtk.model.Manager.create()
    sess = mgr.createSession('exodus')
    rdr = sess.op('read')
    rdr.findAsFile('filename').setValue('disk_out_ref.ex2')
    res = rdr.operate()

crashes inside `smtk::bridge::exodus::Bridge::addModel()`.
All Bridges should reference their owning Manager.
Progress adding relations to Exodus models.
Fix handling of dangling entities.

An iterator was being invalidated and then used.
Recompute it as required.
Finish the first pass of the Exodus bridge.

The bridge now has a read operator that works.
Merge topic 'exodus-bridge'

88ef322 Finish the first pass of the Exodus bridge.
d1535c2 Fix handling of dangling entities.
035bada Progress adding relations to Exodus models.
7b7cbeb All Bridges should reference their owning Manager.
d84f957 Progress on the Exodus-II bridge.
02551f2 Progress on Exodus-II bridge.