Apache Commons Math 3.2, Imglib2 Gaussian fitting

Note that these are only changes to mmstudio and SPIMAcquisition.

Fiji's official Apache Commons Math version is now 3.2; due to some API
incompatibilities, SPIMAcquisition has briefly stopped working. I've
upgraded the version used by SPIMAcquisition, mmstudio, and autofocus.

However, I've simultaneously moved away from our dependence on the Vale
Lab's GaussianFit plugin, for two reasons. First, it isn't sensible to
depend on the output of another plugin; this introduces a build order
necessary to correctly compile the plugin. Second, Imglib2 already
provides the necessary fitting routines, and is arguably the more
standardized approach anyhow. (I had planned this move some time ago, but
the recent commons math update rather forced my hand.)

The more cynical reason, though, is that it saves me the trouble of
immediately upgrading GaussianFit to Commons Math 3.2; there are some
complex fitting routines, the use of which I do not yet understand,
involved in i.e. the MLE class. I will doubtless revisit GaussianFit and
upgrade it, but time is short at the moment and I felt it more pressing to
update the plugin.

Signed-off-by: Luke Stuyvenberg <stuyvenberg@wisc.edu>