Context: remember whether the context is strict

Also add API for setting the strictness later, if desired.

This will be useful so that we can behave strictly (or not)
in later situations, particularly during context injection.

Author: ctrueden

src/main/java/org/scijava/Context.java

@@ -78,6 +78,23 @@ public class Context implements Disposable {
 	/** Master index of all plugins known to the application context. */
 	private final PluginIndex pluginIndex;
 
+	/**
+	 * Whether context creation and injection should behave strictly, failing fast
+	 * when attempting to instantiate a required service which is invalid or
+	 * missing.
+	 * <ul>
+	 * <li>If the flag is false, then the context creation will attempt to
+	 * continue even when a required service cannot be instantiated. Otherwise,
+	 * the constructor will throw an {@link IllegalArgumentException} in that
+	 * situation.</li>
+	 * <li>If this flag is false, then a call to {@link Context#inject(Object)}
+	 * will attempt to catch any errors that occur during context injection
+	 * (notably: {@link NoClassDefFoundError} when scanning for event handler
+	 * methods), logging them as errors.</li>
+	 * </ul>
+	 */
+	private boolean strict;
+
 	/**
 	 * Creates a new SciJava application context with all available services.
 	 * 
@@ -240,6 +257,8 @@ public Context(final Collection<Class<? extends Service>> serviceClasses,
 		this.pluginIndex = pluginIndex == null ? new PluginIndex() : pluginIndex;
 		this.pluginIndex.discover();
 
+		setStrict(strict);
+
 		final ServiceHelper serviceHelper =
 			new ServiceHelper(this, serviceClasses, strict);
 		serviceHelper.loadServices();
@@ -255,6 +274,14 @@ public PluginIndex getPluginIndex() {
 		return pluginIndex;
 	}
 
+	public boolean isStrict() {
+		return strict;
+	}
+
+	public void setStrict(final boolean strict) {
+		this.strict = strict;
+	}
+
 	/**
 	 * Gets the service of the given class.
 	 *