quickjspp v2

[ftk]

This changes the way pointers are stored in JS objects.

	v1 (branch master)	v2 (branch sharedptr)
js object holds opaque pointer to	std::shared_ptr<T>	T
std::shared_ptr<T> conversion	yes	no
qjs::shared_ptr<T> conversion	no	yes
T* conversion	yes	only if T has qjs::enable_shared_from_this<T> as base class
extra allocations when converting from C++ pointer to JS object	yes(slower)	no(faster)
weak_ptr and deleter support	std	not yet
inheritance support	yes	limited
creating c++ objects	new,std::make_shared	qjs::make_shared
<!--	class can evaluate js code	no

current v2 limitations:

• qjs::make_shared needs JSContext
• all qjs::shared_ptr instances need to be destroyed before js context is destroyed

Also fixes bugs where JS properties are not saved

[cykoder]

looks great, will give it a try when ready :)

[cykoder]

small bit of feedback, i tried implementing this branch over last weekend to see how itd go with the changes. requiring classes to be inherited from enable_shared_from_this is a bit of a pain in an existing codebase, was much better in V1 where things can be auto exposed. even if i want to have a class that will only be created natively in JS i still need to inherit from that which doesnt seem nessecary

[luodaoyi]

@SamHellawell I'm agree with you !

enable_shared_from_this is a bad idea.