Update for new commands and primitives.
Update README.md
Rename install-bx.sh to install.sh
Tweak installation instructions.
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update command categories to match wiki and PDF groupings.
Disable unsuitable test in if ENABLE_TESTNET defined.