[WIP] Add dependency injection functionality, Closes #85 (#86)

* misc improvements (as suggested by intellij)

* first draft of the DI functionality (#85)

* address review

* reenabled disabled inspections

* overload registerDependency method

* inject fields of superclasses two and remove invalid sponge default dependency

example/src/main/java/co/aikar/acfexample/SomeHandler.java

@@ -0,0 +1,14 @@
+package co.aikar.acfexample;
+
+public class SomeHandler {
+
+    private String someField;
+
+    public String getSomeField() {
+        return someField;
+    }
+
+    public void setSomeField(String someField) {
+        this.someField = someField;
+    }
+}