Specify that lzma needs to be installed (doesn't really, but to keep things simple), and try to support running pyston not from src/

fix several minor issues found during installing and building

gtest does not compile successfully with "-Wundef", so the following
error will be produced while running unittests:

$ make run_gc_unittests

<snip>
 /path-to-deps/gtest-1.7.0/include/gtest/internal/gtest-port.h:288:6: error: 'GTEST_OS_WINDOWS' is not defined,
       evaluates to 0 [-Werror,-Wundef]
 #if !GTEST_OS_WINDOWS
     ^
 /path-to-deps/gtest-1.7.0/include/gtest/internal/gtest-port.h:299:5: error: 'GTEST_OS_LINUX_ANDROID' is not defined,
       evaluates to 0 [-Werror,-Wundef]
 #if GTEST_OS_LINUX_ANDROID
     ^
<snip>

The workaround for this issue is using '-isystem'.

Result of "import time; print time" can be various from different
distributions, for example:

$ python -c "import time; print time"
<module 'time' from '/usr/lib64/python2.7/lib-dynload/timemodule.so'>

which is diff from the result of "<module 'time' (built-in)>".

So test with result of "print type(time)" instead, which should be
more robust.

The following error was produced when -llzma is not specified:

$ make check
cc -O2 -fPIC -Wimplicit -I../include -c ../test/test_extension/test.c -o ../test/test_extension/test.o -g
cc -shared ../test/test_extension/test.o -o ../test/test_extension/test.so -g
pyston: Compiling runtime/inline/link_forcer.o.bc
pyston: Compiling ../tools/publicize.o
pyston: Linking ../tools/publicize
elfxx.c:193: error: undefined reference to 'lzma_stream_footer_decode'
elfxx.c:200: error: undefined reference to 'lzma_index_buffer_decode'
elfxx.c:204: error: undefined reference to 'lzma_index_size'
elfxx.c:209: error: undefined reference to 'lzma_index_end'
elfxx.c:206: error: undefined reference to 'lzma_index_uncompressed_size'
elfxx.c:209: error: undefined reference to 'lzma_index_end'
elfxx.c:277: error: undefined reference to 'lzma_stream_buffer_decode'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [../tools/publicize] Error 1

Doesn't handle packages or anything other than importing a .py file
(ex zip import, .so, .pyc), but has some basic support for
sys.path and sys.modules.

Not using fixed path for valgrind in Makefile

Just replace "$(HOME)/pyston_deps" with "$(DEPS_DIR)" to make things
keep going well when the dependencies are placed elsewhere.

Turn on some more warnings, though the ones that don't have many false positives aren't very helpful

I think I generated an invalid pyc file by ctrl-C'ing while it was
writing out a file, and it took me a while to figure out why the
parser kept crashing.
Ideally this should be a full checksum.

This means we can have non-consecutive block indices, which
is a prereq for things like merging blocks.
Not sure how worth it this was

Add an extra marker to libunwind so that pyston can ensure it's running on a patched libunwind version

LLVM had some breaking changes that I didn't notice; on the plus
side this new range-iteration style is much nicer.

Removing hardcoded filename in ast.cpp

Add the ability to link against a debug build of libunwind for debugging unwinding issues, and some basic instructions on how to do so

Merge in the changesets that were missed:
- type recording
- better polymorphic IC performance
- build system improvements
- update to what was llvm trunk

Fixing the subtle "bug" apparently makes pyston fail some tests, so I'm backing out on this. It doesn't make much sense that the reverse of NotEq is NotEq, and the reverse of Eq is Eq... this needs to be rechecked by someone that knows the code better than me.

- Fixed subtle bug in getReverseOpName(): the reverse of AST_TYPE::NotEq and the reverse of AST_TYPE::Eq were wrong (ironically, they were reversed!)

- Added zsh dependency
- Fixed subtle typo in LLVM + clang section

Found some bugs in the name analyzer around listcomps; got the unittests back up and running so I can write some more