Correct path plugins issue when reload wPaint

[memiks]

When refresh wPaint, the options.path is added each time.

So this modification will:

• add default image if no image provided
• add option path only if plugin path not already start by it.

Regards,
Frederic.

[pascalbeynel]

I'm interested by this issue, I got the same problem.
If I set path as : /asset/wpaint/, removing and creating a new wpaint (i'm using jquery) will have the path to be /asset/wpaint//asset/wpaint/ so icons are not loaded (provide a 404 on img call).

[pascalbeynel]

Same issue as #73

[memiks]

In fact yes it is the same issue as #73 but I add a test on "menu.items[key].img" in order to add default image if plugin did not have images.