[3/4] jscript: Fix various memory and reference count leaks.

[Jacek Caban]

Hi Rob,

Thanks for your work on jscript. Unfortunately fixing Valgrind on 
jscript is not going to be easy. Most of your fixes are good, except 
clear_global part and "jscript: Fix a circular reference caused by 
object and function objects being able to have properties that are 
objects and functions." patch. I've sent a test showing that Windows 
doesn't do that. To fix it properly we need to implement a garbage 
collector. I've designed it in the very early days of jscript, but I 
never had time to implement it.

Thanks,
     Jacek