Fixes for Mosek

This tweaks the input to ``loadconicproblem!`` so that Mosek passes the (non-SDP) tests. Also reorganizes the tests so that we can test SDP without testing exp. @ulfworsoe

Regarding the list of solvers, we've been looking to have a more systematic way to check solver capabilities: JuliaOpt/JuMP.jl#83. Maybe for the conic interface it makes sense to have each solver implement a function which returns the list of cones that are recognized?