metadata shouldn't be included with NILMTK. Instead load metadata
supplied with dataset. #184
Correctly assign `ac_type` for 6-second data in UK-DALE.  #184
Load one-second SCPM data.  #184
one-sec ElecMeters are marked as 'disabled' by default. #184
MeterGroup has a list of `disabled_meters` which is populated during
`MeterGroup.load()`. #184
implemented `MeterGroup.use_alternative_mains`.  Closes #184
Correctly assigns appliances to disabled meters. #184
Fix bug in `MeterGroup.get_timeframe()` when any meter timeframe is empty.
fix bug where `clip` would fail with `voltage` columns.
Fix bug where `proportion_of_energy_submetered` would fail in any
ElecMeter had 0 energy.
more elegant printed output for `proportion_of_energy_submetered`
Fix bug where we'd try to get metadata for MeterGroup. Tests pass
again now.
more changes
Working version of Hart85 algorithm
added CSVDataStore with reading functionality
Merge branch 'master' of https://github.com/nilmtk/nilmtk
ignores files that start with '.', which often happens in Mac OS
Bugfix in ECO data set converter and metadata change
Restored lower_limit=0 and max_sample_period=0
Merge branch 'master' of https://github.com/beckel/nilmtk

Conflicts:
	nilmtk/dataset_converters/eco/metadata/meter_devices.yaml