Numeric type not preserved in @system

[mforets]

With:

julia> @system(x' = 2x)
LinearContinuousSystem{Float64,IdentityMultiple{Float64}}([2.0])

I expected that the numeric type of this system is an integer. Actually, I like to keep it as is, but we should stress this point in the docs (so i leave this issue open, to consider the documentation update).

[mforets]

See also that:

julia> @system(x' = -2x)
LinearContinuousSystem{Float64,IdentityMultiple{Float64}}([-2.0])

julia> @system(x' = -x)
LinearContinuousSystem{Int64,IdentityMultiple{Int64}}([-1])

In the second case i expected a Float64. (or at least, the two versions should give the same numerical value).