aria2 1.18.8 released

aria2 is a lightweight multi-protocol & multi-source, cross platform download utility operated in command-line. It supports HTTP/HTTPS, FTP, BitTorrent and Metalink.

This releases fixes the bug that aria2 cannot read piped stdin on
mingw32. It also fixes busy loop on mingw32 when SSL/TLS is used. We
also fixed 2 crashes which can occur on all platforms.