Migrate Java code to separate QL repo.

java/ql/src/DeadCode/DeadMethod.qhelp

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+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+
+<overview>
+<p>
+Methods that are never called at runtime are redundant and should be removed.
+</p>
+<include src="DeadCodeSummary.qhelp"/>
+<p>
+Methods are considered dead if at runtime they are never called, either directly, by a method call,
+or indirectly, through a framework or use of reflection. Any method which is not dead is considered
+to be "live".
+</p>
+<p>
+The results can include methods, constructors and initializers. Initializers come in two forms,
+instance initializers and static initializers. For each class there will be at most one dead
+initializer of each type, representing all the initialization of that type in the class.
+</p>
+<include src="DeadCodeDetails.qhelp"/>
+</overview>
+<recommendation>
+<p>
+Before making any changes, confirm that the method is not required by verifying that the only
+dependencies on the method are from other dead methods. This confirmation is necessary because
+there may be project-specific frameworks or techniques which can introduce hidden dependencies.
+If this project is for a library, then consider whether the method is part of the external API,
+and may be used in external projects that are not included in the snapshot.
+</p>
+<p>
+After confirming that the method is not required, remove the method. You will also need to remove
+any references to this method, which may, in turn, require removing other unused classes, methods
+and fields (see Example 1).
+</p>
+<p>
+If the result is a static initializer, then all  <code>static { ... }</code> blocks and
+initializers on static fields are dead within that class. In addition, the lack of static
+initialization implies that all static methods and fields are also dead and can be removed. These
+methods and fields will also be reported separately. In contrast, static nested classes may still
+be live, because constructing or accessing the nested static class does not trigger static
+initialization of the outer class.
+</p>
+<p>
+If the result is an instance initializer, then all instance initializer  <code>{ ... }</code> blocks
+and initializers on instance fields are dead. In addition, the lack of instance initialization
+implies that the class is never constructed, which means that all instance methods and fields are
+also dead and can be removed. These methods and fields will also be reported separately.
+</p>
+<include src="DeadCodeExtraEntryPoints.qhelp"/>
+</recommendation>
+<section title="Example 1">
+<p>
+In the following example, we have a number of methods, and an "entry point" in the form of a main
+method.
+</p>
+<sample src="DeadMethod.java" />
+<p>
+The method <code>liveMethod</code> is called from the main method, and is therefore considered live.
+<code>liveMethod</code> calls <code>otherLiveMethod</code>, which also makes that live.
+</p>
+<p>
+In contrast, <code>deadMethod</code> is never called, and does not represent an entry point, so is
+marked as dead. Likewise, <code>otherDeadMethod</code> is only called from the
+<code>deadMethod</code>, so is also marked as dead.
+</p>
+</section>
+<section title="Example 2">
+<p>
+In this example, we have a test class containing a number of methods.
+</p>
+<sample src="DeadMethodTest.java" />
+<p>
+In this case, no methods are called directly. However, the annotations on the methods indicate that
+this is a test class - specifically, JUnit - and that the methods will be called by the test
+framework when running the tests. <code>testCustomer</code> and <code>setUp</code> are therefore
+considered to be "live".
+</p>
+</section>
+<include src="DeadCodeReferences.qhelp" />
+</qhelp>