Allow running inside Maven unit tests

When Maven's surefire plugin runs unit tests, the URLClassLoader does
actually not list the URLs corresponding to the dependencies. Instead,
surefire tries to be clever and hides those dependencies inside a
single, empty .jar file's manifest's Class-Path: entry.

We are not dumb, so surefire loses: we get the URLs anyway. Hah! Take
this, surefire! *shakes-fist*

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Verify that bare .java 'scripts' find all dependencies

... even when run via surefire...

To that end, we piggy-back on the already existing test for bare .java
"scripts": as scijava-common is a dependency of scripting-java, let's
just use one of scijava-common's utility classes in the bare .java
"script".  That way, the test will only pass when scijava-common's class
is found on the compiler class path.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
JavaEngine: Add all missing Javadocs

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
*Always* use the context class loader

If we ever limit which class loader we use as parent or to discover the
available dependencies by using the class loader that happened to load
MiniMaven, we will be in for a *lot* of trouble in the future, e.g. with
ImageJ 1.x' PluginClassLoader.

So let's not do that. Let's use the current thread's context class loader,
like everywhere else we need a class loader.

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #1 from scijava/surefire

Allow running inside Maven unit tests