Missed range check

Generalize LHEReader so it can read LHE v3.0 input as well

enable all .py files in test to be tests

the test is just to make sure that they successfully run, nothing is done with the data there, but it is helpful to make sure that basic simulation stuff can run at all during development

Correct pi-inelastic names

Update orderings

reword documentation of what "DB material Z" is

add in backwards positron generator

Final formatting

Merge pull request #88 from LDMX-Software/iss86PNModels

Iss86 pn models

fixup string manipulation for scoring planes

We do two things with the input subsystem name:
1. We capitalize the first letter and then append 'ScoringPlaneHits' to
be the collection name
2. We prepend 'sp_' to be the match substring for logical volumes

This means the input subsystem is the name of the scoring planes in the
GDML with the 'sp_' prefix removed.