Cleanups in JNI related code

Removed the malloc version in binary dictionary support -- this has not
really been tested well so far, and the mmap version has been working pretty
well after all.

Several cosmetic fixes etc.

Change-Id: Iad0da58b300b769fb5946a3e73fc96f56215980e
diff --git a/native/jni/jni_common.cpp b/native/jni/jni_common.cpp
index 8e5c508..f2867d7 100644
--- a/native/jni/jni_common.cpp
+++ b/native/jni/jni_common.cpp
@@ -55,8 +55,8 @@
 }
 
 namespace latinime {
-int registerNativeMethods(JNIEnv *env, const char *className, JNINativeMethod *methods,
-        int numMethods) {
+int registerNativeMethods(JNIEnv *env, const char *const className, const JNINativeMethod *methods,
+        const int numMethods) {
     jclass clazz = env->FindClass(className);
     if (!clazz) {
         AKLOGE("Native registration unable to find class '%s'", className);