Cleanup variants and create a new slice for dst

[stefanschneider]

This will also prevent memory leaks :)

Needs this patch to work: https://github.com/mattn/go-ole/pull/22

Ran this https://gist.github.com/stefanschneider/0740ea3c8a39c2e4809c and here is the mem usage:

[maddyblue]

Thank you.