v0.15.9

• allows preRenderMiddleware with router replaces that do not alter query params (closes #89) (6847cd5)
• catches empty filename strings in api/db imports (83e4b33)
• moves HardSourceWebpackPlugin after ExtractTextPlugin (cba5850)
• adds HardSourceWebpackPlugin to prod server webpack (9aee3a8)
• updates postcss-cssnext to v3.1.0 (ded294b)