libbxtables: prefix names and order it #1

It is good practice to prefix names in a library some way so that
it does not clash with external programs' variable names right
on the first try.

This change: rename fw_[cm]alloc to xtables_[cm]alloc and
move the definition from internal.h to xtables.h to avoid
potential compiler warnings.

These functions are intended to fix Jamal's dependency problem in
his tc's ipt action.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
6 files changed