Construct 3 r76

Notes

This build is mostly a batch of bug fixes to help make sure Construct 3 works smoothly for everyone. The main improvements are in the addon SDK where we have two major improvements.

Firstly third-party plugins can now draw text in the editor. This helps fill in a missing feature that C2's SDK had, so hopefully text-based third-party plugins can now also be ported to C3.

Secondly we are working on a major new SDK feature called the custom importer API. This allows plugins to hook in to handling files that are drag-and-dropped in to the editor. The intent is for software like Spriter and Spine (which handle 2D skeletal animation) to write and maintain their own file format importers. For C2 we had a hard-coded importer for Spriter files, but it was difficult to write and maintain, and inflexible (only handling one format, which is somewhat unfair to other software like Spine). Now these developers, and any others, can use the SDK to handle any kind of file format that is dropped in to C3. The API has built-in support for reading from zip files (which we recommend for bundling up related files), and the necessary features to extract data, create sprites, update image data, position and orient instances, and so on. We've added a lot of APIs to the SDK to open up full customisation of projects so addons can do any necessary importing work, but we expect this will take several more releases to get right as we get feedback from developers and fill in any more APIs they need. Still, this is an exciting feature and should open up some new interesting cases for extensibility in Construct 3!