Make Normalizer#Load more forgiving about bools.

Accept any object which implements To_Bool() in places where booleans
are required when deserializing.  This allows for situations where
booleans do not survive round-tripping through the host language and
back.
Remove Clownfish::Obj safety code for Storable.

This has been moved into Clownfish directly.  The CPAN toolchain didn't
like packaging a Clownfish::Obj package with Lucy anyway -- at least not
without a $VERSION, which would have been a bad idea.
Repair `dist` build action.
Fix order-of-destruction error in PostingPool.

Keep the MemoryPool alive while the super destructor runs so that
RawPostings allocated from it are not accessed as dangling references.
Switch from CHY_UNUSED_VAR to CFISH_UNUSED_VAR
Cease using CHY short names

Also include charmony.h directly from .c files where needed preparing
for the next commit.
Don't include charmony.h from Lucy/Util/ToolSet.h

External projects can now use Lucy/Util/ToolSet.h without depending on
Charmonizer.
Fix mixed decs and code in custom XS
Fix some minor numerical precision issues.

Casts, type issues, theoretical truncation, sign comparisons... exposed
courtesy of MSVC's warnings.
Linker flags for Windows Perl build
Add .obj files to .gitignore
Always compile as C++ with MSVC

Although the generated XS is C89-compliant now, it must be compiled in
C++ mode like the rest of the code due to a mismatch between the sizes
of the C++ bool type and the emulated bool type.
Correct cfish library name on Windows
Update .gitignore files for MSVC
Switch to Clownfish's setup_env.sh
Re-add setup_clownfish_env.sh

The old setup_clownfish_env.sh is used by the Buildbot config which I
asked Infra to use. Let's keep it for a while.
Fix DECREF name clash

MinGW's winnt.h also defines DECREF.
Regenerate charmonizer.c for MinGW
Update .gitignore for MinGW
Fix intermittent test-only sort order bug.

Lucy breaks ties by doc_id, but the test did not.  The bug only manifested
once every few hundred iterations because the collisions between scores
occurred rarely.