Include ImgLib2 classes that have been simply removed in the meantime

In a laudable attempt to end the beta phase and offer a stable release
version, the ImgLib2 project removed some functionality that we use
here.

Instead of crying in the rain, we simply copy the code into our project
('shading' it by welcoming it into our package).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Upgrade to current pom-fiji

Due the Big Fiji Upload required by ImgLib2's release being incompatible
with all of the beta versions we relied on, we have to fix the
SPIMAcquisition plugin to allow it to work again.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>