"Displace" option given ability to squish body.

[p0lar-bear]

I'm using sidr in a project of mine and made a small modification to it to resize the body so it fits on the screen with the menu open, and I thought I'd share it. "displace" now takes a string, or false. -false makes the menu slide out without affecting the body. -'slide' pushes the whole body aside, as it did before. -'squish' resizes the body as the sidr slides out.

[momoteRyanmt]

Works great, Thanks

[dfbeauregard]

Nice work, thanks!

[konstantinkv]

for some reason my SIDR was squishing in the first place, this made it slide out normally. Thanks!