PlanarImg: make javadoc more correct

The previous text was a copy-paste from ImagePlusImg (formerly
ImagePlusContainer) and had much leftover text from that transition.
ImagePlusImg: make javadoc more correct

Some questionable statements remain, particularly the bit about being
able to create an ImagePlusImg around an existing ImagePlus -- is this
really possible using the ImagePlusImg class itself? Or must one of
the subclasses be used?
ImagePlusImg: remove bogus parameter declaration
fix a bug in SubpixelEdgelDetection: out-of-bounds access could occur if
the input image size was less than 5 pixels in any dimension.
added javadoc note, stating that SubpixelEdgelDetection requires signed type.
update pom-scijava version to 1.116
Revert "update pom-scijava version to 1.116"

This reverts commit 18be48a8be565e165e8be031600a7fb0c3efa004.
Allow JVM options to be passed for JUnit testing via -DargLine=...

Sometimes, we need to pass JVM options (such as -Djava.awt.headless=true
or -verbose:class) to the JVM running the unit tests. Unfortunately,
the maven-surefire plugin does not seem to expose a command-line
interface, so simulate it by setting argLine to ${argLine}.

This commit was "borrowed" from https://github.com/imagej/imagej's
44f8fcbecd0200619f91ebf2b9b7be4f6df8563c.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Prevent the unit tests from opening a Java cup on MacOSX

On MacOSX, the unit tests which instantiate UI elements -- even if
they do not show them -- open a separate process with a separate dock
icon. This is pretty disruptive when developers run all the unit tests
in the background and try to do something else such as catching up
with their mail.

The apple.awt.UIElement property helps with that.

Suggested by David Philip Marshall in

	http://mid.gmane.org/1374227295612-5004030.post@n6.nabble.com

This commit was "borrowed" from https://github.com/imagej/imagej's
d347d36679d7aabb87c54321398189de2767e179, with an additional adjustment:
due to the (for a unit test) insane memory requirements, we need to adjust
the heap size in the argLine to 512m (128m is not enough).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Prepare call sites of the ImgOpener for SCIFIO 0.8.1

SCIFIO 0.8.1 made ImgOpener#openImg easier to use by avoiding a raw
type. Unfortuntely, this means that we have to cast things if we want
them to be strongly typed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Revert "Revert "update pom-scijava version to 1.116""

Now that we are well-prepared for SCIFIO 0.8.1, we can safely bump
pom-scijava to 1.116.

This reverts commit 531c8e960795374cace358d3f68e2c6a8dceccff.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge remote-tracking branch 'origin/master' into volatile-native
remove ValatileNativeTypes. As they are too special-purpose for imglib2,
for the time being they will live in the BigDataViewer repository
https://github.com/tpietzsch/spimviewer