Update house load model

[dchassin]

This PR fixes issue #1121.

Current issues

1. Snow melt does not work correctly because it cannot calculate the correct rate of snow melt from the snow depth in the weather data.

Code changes

• Update source/cmdarg.cpp to add support for --loadshape[=CSVFILE] [*|SCHEDULE[,...]] command line option.
• Change ELCAP1990 to RBSA2014 as default loadshape (about 1/3 the energy use for basic loads).
• Update module/residential/house_e.{cpp,h} to add support for curtailment and sump pumps.
• Fix python setup so it doesn't make dist/* unnecessarily.

Documentation changes

• Add /Command/Loadshape.md
• Update /Module/Residential/House

Test and Validation Notes

• Update module/residential/autotest that were affected by change in default loadshapes.
• Add module/residential/autotest/test_loadshape_dump.glm
• Add module/residential/autotest/test_sump.glm
• Add module/residential/autotest/test_curtailment.glm