Invalidate any current values corresponding to an input item whenever that input item is updated.
Process input items that could be relevant at file scope at start of each file.
Fix some issues with how default constructed sequences are built if the number of items is not a constant from one file to the next.
Fix bug in start_seq_index when sequence is not indexed by obj_num
Add variable nobjects to demo9, and add required rng at file scope to make it work.
Remove stray debugging print statement, and clean up some config debug statements.
Move where the random seed is set.
typos
Fix demo9.json to comport with changes to demo9.yaml.
Add HISTORY item for this bug fix.
typo
Merge branch 'nobj_bug' of https://github.com/GalSim-developers/GalSim into nobj_bug
Merge pull request #487 from GalSim-developers/nobj_bug

Fix some bugs in config when the number of objects per image is not constant.