Make the simulated click cancel-able

[kurtextrem]

This should fix #71, #69. Might fix #72 too, but not sure.

[bgammill]

#71 is still occurring for me after merging this commit.

[kurtextrem]

@bgammill Does it use event.preventDefault or any other code?

Also, I noticed this doesn't solve a[download] double-downloads. But can be fixed by adding (linkElement.download !== undefined) return