Greatly enhanced common interface compatibility

The common interface now supports all of the possible arguments, and throws warnings for everything else. Since this includes a Hermite interpolation, this handles everything except user-defined Jacobians and the integrator interface. The former is currently stuck, and the latter seems impossible without custom allocators. The only other thing on the agenda is the version upgrade, so we're in a good spot.

v0.6 depwarn fixes

Merge pull request #125 from JuliaDiffEq/0.6

remove unnecessary compats

Compatibility warnings

Merge pull request #122 from JuliaDiffEq/ChrisRackauckas-patch-1

Make callback checking more robust

Update for DiffEqBase v0.15.0

Merge pull request #118 from JuliaDiffEq/common_update

common interface update

Improved memory handling in common and simple interfaces

Merge pull request #113 from JuliaDiffEq/finalizers

Add empty! to simple interface

0.6 compatibility and finalizers

This gives v0.6 compatibility and adds finalizers to the mem types to make the GC more robust.

Improved Common Interface Bindings and Callbacks in the Simplified Interface

Merge pull request #108 from JuliaDiffEq/Pure

Add pure