Cap'n Proto 1.0 release candidate

[Kenton Varda]

Hello capnproto users,

I've created a release candidate for version 1.0 of Cap'n Proto's C++ implementation:

https://capnproto.org/capnproto-c++-1.0.0-rc1.tar.gz

There's nothing particularly special about this release! Frankly, I should probably have applied the 1.0 designation to version 0.6 back in 2017, or maybe even 0.5 back in 2014. It's now been over 10 years since the original 0.1 release and I guess I finally came to my senses, so I decided to go ahead and make this one 1.0 instead of 0.11.

I'll have more details in the blog post when I do the final release next week. In the meantime, please let me know if you find anything obviously wrong with the RC.

-Kenton