Add --windows option to bootstrap.py

Makes it possible to make a native Windows build when using Cygwin Python.
browse: Read ninja's error text from stderr.
Update version number in ninja.vim after recent changes.
Merge pull request #475 from nico/vim

Update version number in ninja.vim after recent changes.
Merge pull request #474 from yannicklm/master

 	NINJA_STATUS: add support of `%p` for percentage
update a comment
correctly open /dev/null in subprocesses

Fixes issue #468.
wrap test in anon namespace
fix test build under clang/system gtest

Tests always need GTEST_HAS_RTTI=0 set, but the code was only
setting it in the --with-gtest branch.  Instead always use the
test-specific cflags when compiling test code.
ninja_syntax.py: don't add trailing space when build has no inputs

Seen in Ninja's configure.py where it creates an "rpmbuild" command.
Merge pull request #467 from ppuryear/browse-error

browse: Read ninja's error text from stderr.
Merge pull request #455 from azuk/master

Make a native Windows build possible when using Cygwin Python.
add a TODO from a pull request
fix all "class" -> "struct"
wrap some overlong lines
rearrange handling of builtin bindings to make rules simpler

Now, a 'build' block can override any special binding like 'command'
or 'description' if it needs to.
update docs to clarify scoping rules
drop the "rules" tool completely

I had already broken this earlier, but the refactor of variable handling
broke it completely.
fix build on non-Linux glibc systems

ninja-build does not build on non-Linux archs, such as
GNU/kFreeBSD and GNU/Hurd.

The problem is that the GetProcessorCount() implementation for these
architectures is the sysconf() one, but <unistd.h> has not been
included, causing sysconf() and _SC_NPROCESSORS_ONLN to not be
declared. Another solution (which is the one I chose) is to make use
of the "linux" implementation which uses get_nprocs(), which is a GNU
extension and thus available for anything using GNU libc.
always set GTEST_HAS_RTTI=0 in all testing code