Throw error for ==(::DecoratedInterval, ::Interval)

[dpsanders]

Currently:

julia> DecoratedInterval(x) == x
ERROR: type DecoratedInterval has field offset -1431655776 that exceeds the page size
Stacktrace:
 [1] promote_rule at /Users/dpsanders/.julia/dev/IntervalArithmetic/src/decorations/intervals.jl:99 [inlined]
 [2] promote_type(::Type{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Float64}}}}}}}}}}}}}}}}}}}}}}}}}}}}, ::Type{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{Float64}}}}}}}}}}}}}}}}}}}}}}}}}}}}) at ./promotion.jl:223
 [3] promote_result(::Type{T} where T, ::Type{T} where T, ::Type{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Float64}}}}}}}}}}}}}}}}}}}}}}}}}}}}, ::Type{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{DecoratedInterval{Interval{Float64}}}}}}}}}}}}}}}}}}}}}}}}}}}}) at ./promotion.jl:237
 [4] promote_type at ./promotion.jl:223 [inlined]
 ... (the last 2 lines are repeated 25 more times)
 [55] _promote at ./promotion.jl:258 [inlined]
 [56] promote at ./promotion.jl:282 [inlined]
 [57] ==(::DecoratedInterval{Float64}, ::Interval{Float64}) at ./promotion.jl:348

cf #219, #220