Appveyor config for windows build+installer (#1302)

* appveyor

* proper dist name

* quote

* win-build config

* proper build section

* tests in release

* plugin dir

* cache binaries

* quotes

* escaped quotes

* forces user dir

* fixes

* syntax

* proper cahce dir

* quotes?

* root nsis instead of bin

* submodules init

* artifact path fix

* no submodule

* raw link here

* another way to force cargo cache

* include vc++ 2015 redist

* fix name of the dist

* ETHCORE -> Ethcore