Idris2 Versions Save

Highlights include:

• Size-change graphs are now matrices, faithfully implementing [Lee, Jones, and Ben-Amram; 2001]
• Elaborator scripts can now access project files, allowing for type-providers and similar
• Warnings on conflicting fixity declarations along with %hide support for these
• Numerous doc and error message enhancements, bug fixes, performance improvements, and much more

See the CHANGELOG for full details.

This is to solve a couple of build issues. It requires either Idris v0.4.0, or the bootstrap code, to build.

Chez Scheme 9.5 (possibly earlier versions too, I haven't checked) is now sufficient for the bootstrap build, like previous versions of Idris. Also removed the dependency on sha256sum since this is not portable.