re-enable native_pbc

use new t/native_pbc/testdata templates to generate pbc's,
change string to use binary and utf8 encodings,
update mk_native_pbc.
TODO: little-endian pbc files missing, preparing a 8_le qemu image to generate them.
[GH #394] Revamp native_pbc: t/native_pbc/Test.pm

Simplify tests with a common t/native_pbc/Test.pm library.
Delete unneeded pbc files.
Update ppc32 t/native_pbc files.

TODO: endian-conversion fails
refactor t/native_pbc/ test ids

Parrot::Test had the odd assumption that testing pbc can only be done for
native_pbc tests, and that the tests must be of _<int>++.pbc.
We pass now the filename as first arg to pbc_output_is() and check if it exists.

So we can use now readable test names.
mk_packfile_pbc refactor with t/native_pbc/testdata/annotations.pir
mv t/native_pbc/testdata/string.pir t/native_pbc/testdata/string.pasm
Fixed pbc_header.pl, usage docs, improved version tests

Fixed pbc_header.pl to query and update pbc versioninfo in headers.
Improved release manager guide to update native_pbc headers when PBC_COMPAT
was not changed.
Add better skip message to tests when just the Parrot version was bumped, but
bc version matches.
Bumped all native_pbc/*.pbc headers to 4.7.0.
native_pbc: refactor skip messages
Revive pbc

The parrot utils could not load pbc compatible, but older pbc fils anymore
because opslib directories and the init function hardcoded the parrot version
(even with patch!) and not the PBC_COMPAT version.

Replaced all parrot version triples in the pbc format with the PBC version duple.
parrot utils can now load older but compatible pbc files (again).

Replaced the hardcoded version numbers with c preprocessor macros in the
bootstrapped opslib sources and headers, to be more independent and simplier
implementation. If the ops did not change, the ops do not need to get regenerated
anymore for each version bump.
The Ops::Emitter version method is not used anymore, since bootstrap-ops has
been simplified.

Sanified the Makefile by adding missing dependencies and do proper identation
for depends and commands. Prev. line-broken depends were not visually
indistuingishible from commands, and line-broken commands neither.

Store PBC_MAJOR and PBC_MINOR in the config hash, stored by auto::revision.

Bump PBC_COMPAT to 13.0, the opslib directories store now only two version
numbers, not three.
fix tools/dev/mk_native_pbc: use new ids
regenerate native_pbc for intel 64bit
tools/dev/mk_native_pbc comments
update native_pbc files for little-endian
fixed the rest of the pbc number converters.

big-endian still untested, need a UltraSparc64 to confirm.
native_pbc big-endian 32-bit regenerated.

endian-ness conversion [GH #807] still broken.
update number test matrix with big-endian results

[GH #807]: broken 4_8_le ->4_16_be, 4_12_le -> 4_16_be, 8_16_le -> 4_16_be,  8_8_le -> 4_16_be
8_16_le->4_8_be, 4_12_le -> 4_8_be, 4_8_le -> 4_8_be
cvt_num16_num8 in i386 still broken

No ticket yet, but I am working on it.
rebase native_pbc onto RELEASE_4_10_0
rename ops2c core init_func

We only need one PARROT_CORE_OPLIB_INIT, reuse
the prev. PARROT_DYNOP_CORE_INIT definition.
We do not need pbcversion.h in core_ops, once in config.h is enough.
Updated 8_le native_pbc, fix opsc/08-emitter.t