Add setup.py for installation

Add setup.py for installation.

BUG=119
Committed: http://code.google.com/p/gyp/source/detail?r=767

[Evan Martin, 2009-12-09 00:40:06]

http://codereview.chromium.org/460153/diff/1/3
File setup.py (right):

http://codereview.chromium.org/460153/diff/1/3#newcode12
setup.py:12: install_cmd = self.get_finalized_command('install')
mixture of 2 and 4 space tabs :<

http://codereview.chromium.org/460153/diff/1/3#newcode14
setup.py:14: bin_dir = os.path.join(lib_dir, "..", "..", "..", "bin");
trailing semi D:

[sgk, 2009-12-09 10:02:43]

http://codereview.chromium.org/460153/diff/1/3
File setup.py (right):

http://codereview.chromium.org/460153/diff/1/3#newcode13
setup.py:13: lib_dir = getattr(install_cmd, 'install_lib')
Readability:

install_cmd.install_lib

(But should use install_scripts instead, anyway--see next comment.)

http://codereview.chromium.org/460153/diff/1/3#newcode14
setup.py:14: bin_dir = os.path.join(lib_dir, "..", "..", "..", "bin");
Don't infer the bin directory like this.  For different versions of
distutils+Python, it won't necessarily be at the same depth relative to the lib
directory.  Instead, just use the "install_scripts" attribute:

bin_dir = install_cmd.install_scripts

(This also makes the setup.py a little more platform-independent and allow you
to take out the "if sys.platform == 'linux2'" block, although it would need to
be installed as 'gyp.py' on Windows.)

http://codereview.chromium.org/460153/diff/1/3#newcode16
setup.py:16: distutils.file_util.copy_file('gyp', gyp_bin)
This will try to install the file even when the -n option is used.  Instead:

distutils.file_util.copy_file('gyp', gyp_bin, dry_run=self.dry_run)

http://codereview.chromium.org/460153/diff/1/3#newcode17
setup.py:17: os.chmod(gyp_bin, 0755)
This will try to chmod() even when the -n option is used (when it may not
exist).  It would also be helpful to report the chmod.  So:

from distutils import log
log.info('changing mode of %s' % gyp_bin)
if not self.dry_run:
    os.chmod(gyp_bin, 0755)

[sgk, 2009-12-09 17:13:20]

Just hit me when I woke up, distutils knows how and where to install
scripts, so this is all (or should be) doable without the custom
install function, and with support for the install_lib and install_scripts
subcommands that install just those portions.  Untested, but should be in the
ballpark:

from distutils.command.install import install
from distutils.command.install_lib import install_lib
from distutils.command.install_scripts import install_scripts
        .
        .
        .
setup(
    .
    .
    .
    scripts = ['gyp'],
    cmdclass = {'install': install,
                'install_lib': install_lib,
                'install_scripts': install_scripts},
)

[agl, 2009-12-11 19:24:21]

I ran the commands that fta listed in the bug, and here's the contents of the
resulting root:

./usr
./usr/bin
./usr/bin/gyp
./usr/lib
./usr/lib/python2.6
./usr/lib/python2.6/site-packages
./usr/lib/python2.6/site-packages/gyp-0.1.egg-info
./usr/lib/python2.6/site-packages/gyp
./usr/lib/python2.6/site-packages/gyp/SCons.py
./usr/lib/python2.6/site-packages/gyp/MSVSProject.py
./usr/lib/python2.6/site-packages/gyp/generator
./usr/lib/python2.6/site-packages/gyp/generator/make.py
./usr/lib/python2.6/site-packages/gyp/generator/scons.py
./usr/lib/python2.6/site-packages/gyp/generator/msvs.py
./usr/lib/python2.6/site-packages/gyp/generator/xcode.py
./usr/lib/python2.6/site-packages/gyp/generator/gypd.py
./usr/lib/python2.6/site-packages/gyp/generator/gypsh.py
./usr/lib/python2.6/site-packages/gyp/generator/__init__.py
./usr/lib/python2.6/site-packages/gyp/common.py
./usr/lib/python2.6/site-packages/gyp/MSVSNew.py
./usr/lib/python2.6/site-packages/gyp/xcodeproj_file.py
./usr/lib/python2.6/site-packages/gyp/MSVSUserFile.py
./usr/lib/python2.6/site-packages/gyp/__init__.py
./usr/lib/python2.6/site-packages/gyp/MSVSToolFile.py
./usr/lib/python2.6/site-packages/gyp/MSVSVersion.py
./usr/lib/python2.6/site-packages/gyp/input.py

[sgk, 2009-12-11 19:28:50]

lgtm