Reduce object nesting level from 1500 to 700

On Windows, creating a nested object 1500 levels deep crashes
the shell with a stack overflow.  This is presumably because of
the default stack size of 1 MB on Windows; the default stack
size on Linux is 8 MB.  So, reduce the nesting level from 1500
to 700 to make the test pass on Windows.

This doesn't address the actual stack overflow problem, which
also exists on Linux but requires a larger number.  Testing with
20000 crashes Linux and Mac OS X with segfaults.

jstests/nestedobj1.js

@@ -16,8 +16,7 @@ t = db.objNestTest;
 t.drop();
 t.ensureIndex({a:1});
 
-nestedObj = makeNestObj(1500);
-print(nestedObj);
+nestedObj = makeNestObj(700);
 
 t.insert( { tst : "test1", a : nestedObj }, true );
 t.insert( { tst : "test2", a : nestedObj }, true );
@@ -28,5 +27,5 @@ assert.eq(1, t.find({tst : "test2"}).count(), "find test");
 
 //make sure index insertion failed (nesting must be large enough)
 assert.eq(0, t.find().hint({a:1}).explain().n, "index not empty");
-
+print("Test succeeded!")
 }