Remove old carrier efficiency feature

This is no longer used, and was replaced with the introduction of
Atlas+Refinery.

Closes #562
Improve formatting of converter data

Closes quintel/etmodel#1684
Ref quintel/etmodel#1276
Whitespace fix for Ruby 1.9
Update libraries to support Ruby 2.1
Fix presets bulk_update task

Adds the "key" attribute to presets, matching the value from the Atlas
preset.
Fix preset trying to set a "key" on a scenario
Don't forget to set the preset key >.<
Fixed typo in defaults.
First draft of LOLE functions
Add a "demand" parameter to loss_of_load_expectation

Since one graph cannot read values from another (i.e. future graph
reading a property of the present graph), a "demand" parameter has been
added to loss_of_load_expectation so that the demand can be calculated
elsewhere, and then passed into the calculation.

For example:

  # LOLE Demand Query

  V(GRAPH(), final_demand_for_electricity) +
    V(GRAPH(), energy_sector_final_demand_for_electricity) +
    QUERY_PRESENT(-> { V(energy_power_hv_network_loss, demand) })

  # LOLE Calculation

  V(GRAPH(), loss_of_load_expectation(
    Q(lole_demand), Q(reliable_electricity_production_capacity)))