Release 0.2.0

breaking change: There is now a std feature, enabled by default, along with the implication that building without this feature makes this a #[no_std] crate.
- The Float and Real traits are only available when std is enabled.
- Otherwise, the API is unchanged, and num-traits 0.1.43 now re-exports its items from num-traits 0.2 for compatibility (the semver-trick).

Contributors: @cuviper, @termoshtt, @vks

Release 0.1.43

num-traits now has its own source repository at rust-num/num-traits.
ParseFloatError now implements Display.
The new AsPrimitive trait implements generic casting with the as operator.
The new CheckedShl and CheckedShr traits implement generic support for the checked_shl and checked_shr methods on primitive integers.
The new Real trait offers a subset of Float functionality that may be applicable to more types, with a blanket implementation for all existing T: Float types.

Thanks to @cuviper, @Enet4, @fabianschuiki, @svartalf, and @yoanlcq for their contributions!

No prior release notes were kept. Thanks all the same to the many contributors that have made this crate what it is!