Add some Javadocs to Align_Image#align()

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Align Image: Optionally skip scaling and/or rotation

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Align Image: support color images, too

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
IJ Hacker: fix an NPE with ImageJ 1.47a

We should be careful with names of fields we add; if we use too generic
a name (e.g. 'name') it is likely that our field gets shadowed by,
or shadows itself, a field of ImageJ 1.x.

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