Update bundled Boost to fix recent-Linux compile errors

from 1.53 to 1.55

uintptr_t was undefined in some Boost headers.  Most likely
they'd been including some system headers that used to include
other system headers that define uintptr_t.  The new version of
Boost seems to have fixed this bug.
Merge branch 'fixes'
fix spelling
remove a set of old no-longer-relevant notes
Document how the source code is organized (in the README)
add info to README
Disable warning '-Wunused-local-typedefs'

Both Boost code and our code triggered this warning, our code
in macros that make it not quite trivial to fix.  I estimate it's
not important/useful enough a warning to keep it on.
Fix -Wconstexpr-not-const (fixes compatibility with C++1y/C++14)

"'constexpr' non-static member function will not be
 implicitly 'const' in C++1y; add 'const' to avoid
 a change in behavior"

We'd removed those consts because compilers had warned
they were redundant, but now the standard is changing
to be more sensible and the compilers are following along.

(GCC 4.8.2's libstdc++ is incompatible with C++1y's removal
of 'gets()', so I haven't yet been able to test that Lasercake
works with Clang 3.4's -std=c++1y, but at least this legitimate
warning is fixed.)
delete out-of-date comment

--help and --version now say Lasercake's version number.
Add release-build script for reproducibly building releases

It likely doesn't meet the standards of deterministic builds
( http://gitian.org/ , https://wiki.debian.org/ReproducibleBuilds )
yet, but it makes it much easier to make releases and to
be confident that I'll be able to know with high confidence,
even years later, exactly how the releases were made.

This script currently supports building for Linux and Windows.
DEVELOPER_README: remove dependence on atool/apack

The common command `zip` (Info-ZIP) has a fairly
simple and standard way to create an archive and
atool uses it.
OS X: build system: make putting Lasercake in a .app bundle optional
make dev-build.py work for more platforms

Windows had been broken in that running tests called
`Lasercake` rather than `Lasercake.exe`.

OSX when creating an OS X bundle (cmake -DOSX_BUNDLE)
had been broken too.  Now it works.  (It's slower to create a
bundle than not, so dev builds likely don't want to build bundles,
but it's good to have it work.)
CMakeLists: let user choose program name (e.g. to add version number)

This affects the binary name and (where relevant) release archive name.
Specify OS X release .dmg name rather.

Previously it used the default Lasercake-{version}-Darwin.dmg,
but we release with Lasercake-{version}-OSX.dmg.
fix release-build git dir usage

(I'd thought --git-dir was an alternative to `cd`ing, but
actually it sets only the metadata directory and treats
the current directory as the git working directory.)
release-build.py: fix Python 2.6 compatibility
release-build: add (limited) OS X support
Make dev-build.py work when called from another directory
Fix/improve/convert-to-Python gdb-lasercake and callgrind-lasercake