This required some rework of the libc selection, as moxiebox is a layer on
top of another libc - newlib.
Also, moxiebox'es host VM (`sandbox`) needs a libcrypto on the host. We will
not have it if we're cross-compiling a canadian cross. Fortunately, all moxiebox
needs from libcrypto is SHA256, and it already includes a standalone implementation
of SHA256 in its runtime. Provide a little wrapper that allows moxiebox use
that implementation for the host binary, too.
Also, automate collecting/printing the list of all packages in a given category
(e.g. LIBC or COMP_TOOLS), generate a list of all Kconfig symbols for a given
category.
Signed-off-by: Alexey Neyman <stilor@att.net>