Sciter v.2 preview + gradients

I’ve added support of gradients in H-SMILE core. On the right are some of renderings with debug output (line with arrow) showing gradient vector used in each case. Sciter v.2 SDK preview is available here: terrainformatica.com/sciter/sciter2-tech-preview.zip Radial and linear gradients are supported. Implementation of radial gradients follows this draft: dev.w3.org/csswg/css3-images/#radial-gradients Implementation of linear gradients in…