Drop boost runtime dependencies

[3Hren]

Currently there are two dependencies:

• Boost::Thread (for TLS).
• Boost::System (for ASIO).

Drop them both.

[gwihlidal]

Hello,

I would love to use blackhole (it looks great!), but the reliance on boost is a no-no for my team, and in addition to boost system/thread, it also looks like attribute.hpp depends on boost mpl. Any update on the full removal of boost?

Additionally, blackhole doesn't compile on Windows (I'm using VS 2017)

Thank you,
Graham

[jmatzen]

+1 for this. Boost is a non-starter for me.