Build tools before tests
Check for a2x if --enable-docs-build=yes
Add API for interactive prompting, change --no-ask-password to --non-interactive

Automatically detect non-interactive mode using isatty on linux.
Move --help parameter info to the right manual section
Add doc section about running megatools from console
Rewrite megareg to support interactive prompt for sign up link, and ephemeral accounts
Improve error reporting for anon account login