Fix Compiler to load from its own ClassLoader

The compiler class needs to ensure the PrologClassLoader that will
be run to perform the Prolog->Java translation can actually see the
Prolog predicates containing the compiler. By default the ClassLoader
will be the system ClassLoader, which might not contain the Compiler.

src/compiler/Compiler.java

diff --git a/src/compiler/Compiler.java b/src/compiler/Compiler.java
index ed57398..6b446cc 100644
--- a/src/compiler/Compiler.java
+++ b/src/compiler/Compiler.java
@@ -2,6 +2,7 @@
 import com.googlecode.prolog_cafe.lang.BufferingPrologControl;
 import com.googlecode.prolog_cafe.lang.ListTerm;
 import com.googlecode.prolog_cafe.lang.Prolog;
+import com.googlecode.prolog_cafe.lang.PrologClassLoader;
 import com.googlecode.prolog_cafe.lang.PrologException;
 import com.googlecode.prolog_cafe.lang.SymbolTerm;
 import com.googlecode.prolog_cafe.lang.Term;
@@ -97,6 +98,7 @@
     /** Initialize a new compiler instance. */
     public Compiler() {
       pcl = new BufferingPrologControl();
+      pcl.setPrologClassLoader(new PrologClassLoader(Compiler.class.getClassLoader()));
       options = EnumSet.noneOf(Option.class);
       enableDefaultOptions();
     }