Use exec and proper quoting in top-level gyp command.

R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/74243002

git-svn-id: http://gyp.googlecode.com/svn/trunk@1787 78cadc50-ecff-11dd-a971-7dbc132099af
diff --git a/gyp b/gyp
index a157f34..b53a6dd 100755
--- a/gyp
+++ b/gyp
@@ -3,5 +3,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-BASE=`dirname $0`
-python $BASE/gyp_main.py "$@"
+set -e
+base=$(dirname "$0")
+exec python "${base}/gyp_main.py" "$@"