bind: use lowercase method names for Java binds

There was a discussion a year ago about making methods and types
lowercase in ObjC (https://github.com/golang/go/issues/12889),
which was done (https://go-review.googlesource.com/#/c/15780/),
alas the suggested Java lower casing was never addressed.

This CL converts all generated Java methods to lower case.

Change-Id: Ia2f28519bc59362877881636109ddfc651b24960
Reviewed-on: https://go-review.googlesource.com/28494
Reviewed-by: Elias Naur <elias.naur@gmail.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

bind/testdata/interfaces.java.golden

@@ -7,7 +7,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface Error {
-    public void Err() throws Exception;
+    public void err() throws Exception;
     
 }
 
@@ -20,7 +20,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface I {
-    public int Rand();
+    public int rand();
     
 }
 
@@ -33,7 +33,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface I1 {
-    public void J();
+    public void j();
     
 }
 
@@ -46,7 +46,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface I2 {
-    public void G();
+    public void g();
     
 }
 
@@ -59,7 +59,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface I3 {
-    public I1 F();
+    public I1 f();
     
 }
 
@@ -72,8 +72,8 @@ package go.interfaces;
 import go.Seq;
 
 public interface LargerI extends I, SameI {
-    public void AnotherFunc();
-    public int Rand();
+    public void anotherFunc();
+    public int rand();
     
 }
 
@@ -86,7 +86,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface SameI {
-    public int Rand();
+    public int rand();
     
 }
 
@@ -99,7 +99,7 @@ package go.interfaces;
 import go.Seq;
 
 public interface WithParam {
-    public void HasParam(boolean p0);
+    public void hasParam(boolean p0);
     
 }
 
@@ -114,7 +114,7 @@ import go.Seq;
 public abstract class Interfaces {
     static {
         Seq.touch(); // for loading the native library
-        init();
+        _init();
     }
     
     private Interfaces() {} // uninstantiable
@@ -122,52 +122,52 @@ public abstract class Interfaces {
     // touch is called from other bound packages to initialize this package
     public static void touch() {}
     
-    private static native void init();
+    private static native void _init();
     
     private static final class proxyError extends Seq.Proxy implements Error {
         proxyError(Seq.Ref ref) { super(ref); }
     
-        public native void Err() throws Exception;
+        public native void err() throws Exception;
     }
     private static final class proxyI extends Seq.Proxy implements I {
         proxyI(Seq.Ref ref) { super(ref); }
     
-        public native int Rand();
+        public native int rand();
     }
     private static final class proxyI1 extends Seq.Proxy implements I1 {
         proxyI1(Seq.Ref ref) { super(ref); }
     
-        public native void J();
+        public native void j();
     }
     private static final class proxyI2 extends Seq.Proxy implements I2 {
         proxyI2(Seq.Ref ref) { super(ref); }
     
-        public native void G();
+        public native void g();
     }
     private static final class proxyI3 extends Seq.Proxy implements I3 {
         proxyI3(Seq.Ref ref) { super(ref); }
     
-        public native I1 F();
+        public native I1 f();
     }
     private static final class proxyLargerI extends Seq.Proxy implements LargerI {
         proxyLargerI(Seq.Ref ref) { super(ref); }
     
-        public native void AnotherFunc();
-        public native int Rand();
+        public native void anotherFunc();
+        public native int rand();
     }
     private static final class proxySameI extends Seq.Proxy implements SameI {
         proxySameI(Seq.Ref ref) { super(ref); }
     
-        public native int Rand();
+        public native int rand();
     }
     private static final class proxyWithParam extends Seq.Proxy implements WithParam {
         proxyWithParam(Seq.Ref ref) { super(ref); }
     
-        public native void HasParam(boolean p0);
+        public native void hasParam(boolean p0);
     }
     
     
-    public static native int Add3(I r);
-    public static native void CallErr(Error e) throws Exception;
-    public static native I Seven();
+    public static native int add3(I r);
+    public static native void callErr(Error e) throws Exception;
+    public static native I seven();
 }