Announcing Drone 0.13

This is an intermediate release on the way of adding RISC-V architecture support.

To compile on current Rust nightly, a breaking change was needed. Previously drone_core::inventory module was based on const_generics unstable feature. But lately it was noticeably limited. We decided to use typenum crate instead, which slightly changed public signatures of inventory module.

Many macros, including thr!, heap!, reg!, has changed their syntax. The goal of new syntax is to make Drone macros self-documenting, intuitive and uniform.

Items deprecated in version 0.12 was removed. This includes some stream methods on thread tokens and drone_cortexm::drv::fpu module.

Interrupt bindings, which were used for type-checking interrupt numbers, were removed. There were two reasons: many vendor SVD files tend to contain garbage in interrupt descriptions, and this feature was useless in generic contexts.

Also this release adds a new experimental target - Texas Instruments CC2538, and a new experimental crate - drone-tisl-map, which is the first Drone crate driven solely by the community!