State.energy.comp as a dictionary or structure parameters

[JosePereiraUA]

State.energy.comp can be:

mutable struct Energy <: AbstractEnergy
    total::Float64
    comp::Dict{String, Float64}
end

or

mutable struct Energy <: AbstractEnergy
    total::Float64
    bonds::Float64
    angles::Float64
    dihedrals::Float64
    coulomb::Float64
    (...)
end

[JosePereiraUA]

As of bdcc9ac17d5fd584a114ebe54cb31f62f6948c98 (May 3):

• State.energy.comp is a dictionary. The reasoning is that, this way, it makes obsolete the existence of both AbstractEnergy and NullEnergy types, while making possible the addition of new energy components by the end user.