1.0.15

[neuroscr]

• introduce web api (tries to bind to 22000 on localhost by default)
• introduce show-quorum
• introduce import
• introduce keys
• fix download-blockchain
• centos8 fixes
• turn off always showing the logo
• fix qun_ip (it's tied to the p2p_ip)
• trim new lines from stop blockchain output
• download-binaries now just runs check-system if systemd is enabled
• download-binaries fall back to last release if the current one doesn't have a binary for your platform
• improve status blockchain error handling