bundle2: move all parts into a `bx2` namespace
All currently core parts are moved to a `bx2` namespace (for "bundle 2
experimental"). This should avoid conflicts between the final stable
format and the one about to be released.
all()
draft()
::tip
draft() and ::tip
0::tip
roots(0::tip)
author(lmoscovicz)
author(mpm)
author(lmoscovicz) or author(mpm)
tip:0
max(tip:0)
min(0:tip)
0::
min(0::)
roots((tip~100::) - (tip~100::tip))
::p1(p1(tip))::