not work in some scenarios

[zbryikt]

Not work when libraries

• pollute global object ( such as seedrandom )
• use asynchronous function without proper encapsulation
• dynamically create and access global object

Libraries may have issues when

• modify base module ( like d3 ). Try nested dependency to solve this.

[zbryikt]

- pollute global object ( such as seedrandom )

this happens to all module systems ( esmodule, commonjs ). I don't think we will have a way to solve all of these unless we put every context in their own iframe.

[zbryikt]

 - use asynchronous function without proper encapsulation
 - dynamically create and access global object

this is fixed by wrapping lib codes in function scope, and overwrite global, self and window variable.

 - modify base module ( like d3 ). Try nested dependency to solve this.

added context support to load library on.

[zbryikt]

we now don't populate window object in context function - it just doesn't work. two overlapped context may corrupt our stack.

however we already use _wrapper to take care of script loading, and we also have context object for using loaded libraries, so I don't think we will need this behavior ( populate window object ) from now on.

[zbryikt]

re-enable populating window object in context but only for in-frame context, since in frame context we don't use _wrapper.