Add support for building targets directly from gyp.

gyptest.py

 #!/usr/bin/env python
 
 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 __doc__ = """
 gyptest.py -- test runner for GYP tests.
 """
 
@@ skipping 153 matching lines @@
   parser.add_option("--path", action="append", default=[],
             help="additional $PATH directory")
   parser.add_option("-q", "--quiet", action="store_true",
             help="quiet, don't print test command lines")
   opts, args = parser.parse_args(argv[1:])
 
   if opts.chdir:
     os.chdir(opts.chdir)
 
   if opts.path:
-    os.environ['PATH'] += ':' + ':'.join(opts.path)
+    extra_path = [os.path.abspath(p) for p in opts.path]
+    extra_path = os.pathsep.join(extra_path)
+    os.environ['PATH'] += os.pathsep + extra_path
 
   if not args:
     if not opts.all:
       sys.stderr.write('Specify -a to get all tests.\n')
       return 1
     args = ['test']
 
   tests = []
   for arg in args:
     if os.path.isdir(arg):
@@ skipping 70 matching lines @@
     report("No result from", no_result)
 
   if failed:
     return 1
   else:
     return 0
 
 
 if __name__ == "__main__":
   sys.exit(main())