Add a few overloads to keep binary compatibility with 2.0

Author: slandelle

client/src/main/java/org/asynchttpclient/RequestBuilderBase.java

@@ -180,6 +180,13 @@ public T clearHeaders() {
         return asDerivedType();
     }
 
+    /**
+     * @see #setHeader(CharSequence, Object)
+     */
+    public T setHeader(String name, Object value) {
+        return setHeader((CharSequence) name, value);
+    }
+
     /**
      * Set uni-value header for the request
      *
@@ -192,6 +199,13 @@ public T setHeader(CharSequence name, Object value) {
         return asDerivedType();
     }
 
+    /**
+     * @see #setHeader(CharSequence, Iterable)
+     */
+    public T setHeader(String name, Iterable<?> values) {
+        return setHeader((CharSequence) name, values);
+    }
+    
     /**
      * Set multi-values header for the request
      *
@@ -204,6 +218,13 @@ public T setHeader(CharSequence name, Iterable<?> values) {
         return asDerivedType();
     }
 
+    /**
+     * @see #addHeader(CharSequence, Object)
+     */
+    public T addHeader(String name, Object value) {
+        return addHeader((CharSequence) name, value);
+    }
+
     /**
      * Add a header value for the request. If a header with {@code name} was setup for this request already -
      * call will add one more header value and convert it to multi-value header
@@ -222,6 +243,13 @@ public T addHeader(CharSequence name, Object value) {
         return asDerivedType();
     }
 
+    /**
+     * @see #addHeader(CharSequence, Iterable)
+     */
+    public T addHeader(String name, Iterable<?> values) {
+        return addHeader((CharSequence) name, values);
+    }
+
     /**
      * Add header values for the request. If a header with {@code name} was setup for this request already -
      * call will add more header values and convert it to multi-value header