Embed R8/ProGuard rules in JAR.

Note that Android specific rules remain in the Android AAR.

objectbox-java/src/main/resources/META-INF/proguard/objectbox-java.pro

@@ -0,0 +1,43 @@
+# When editing this file, also look at consumer-proguard-rules.pro of objectbox-android.
+
+-keepattributes *Annotation*
+
+# Native methods
+-keepclasseswithmembernames class io.objectbox.** {
+    native <methods>;
+}
+
+# For __boxStore field in entities
+-keep class io.objectbox.BoxStore
+
+-keep class * extends io.objectbox.Cursor {
+    <init>(...);
+}
+
+# Native code expects names to match
+-keep class io.objectbox.relation.ToOne {
+    void setTargetId(long);
+}
+-keep class io.objectbox.relation.ToMany
+
+-keep @interface io.objectbox.annotation.Entity
+
+# Keep entity constructors
+-keep @io.objectbox.annotation.Entity class * { <init>(...); }
+
+# For relation ID fields
+-keepclassmembers @io.objectbox.annotation.Entity class * {
+    <fields>;
+}
+
+-keep interface io.objectbox.converter.PropertyConverter {*;}
+-keep class * implements io.objectbox.converter.PropertyConverter {*;}
+
+-keep class io.objectbox.exception.DbException {*;}
+-keep class * extends io.objectbox.exception.DbException {*;}
+
+-keep class io.objectbox.exception.DbExceptionListener {*;}
+-keep class * implements io.objectbox.exception.DbExceptionListener {*;}
+
+# for essentials
+-dontwarn sun.misc.Unsafe