Improvement: better ruby from_* support in well_known_types.rb

* Added capability to support from_* requests properly by adding class methods and returning self for instance methods
    * `Timestamp.from_time`
    * `Value.from_ruby`

ruby/lib/google/protobuf/well_known_types.rb

@@ -82,9 +82,14 @@ def to_time
         end
       end
 
+      def self.from_time(time)
+        Timestamp.new(seconds: time.to_i, nanos: time.nsec)
+      end
+
       def from_time(time)
         self.seconds = time.to_i
         self.nanos = time.nsec
+        self
       end
 
       def to_i
@@ -131,6 +136,34 @@ def to_ruby(recursive = false)
           raise UnexpectedStructType
         end
       end
+
+      def self.from_ruby(value)
+        ret = Value.new
+        case value
+        when NilClass
+          ret.null_value = 0
+        when Numeric
+          ret.number_value = value
+        when String
+          ret.string_value = value
+        when TrueClass
+          ret.bool_value = true
+        when FalseClass
+          ret.bool_value = false
+        when Struct
+          ret.struct_value = value
+        when Hash
+          ret.struct_value = Struct.from_hash(value)
+        when ListValue
+          ret.list_value = value
+        when Array
+          ret.list_value = ListValue.from_a(value)
+        else
+          raise UnexpectedStructType
+        end
+
+        ret
+      end
 
       def from_ruby(value)
         case value
@@ -155,6 +188,8 @@ def from_ruby(value)
         else
           raise UnexpectedStructType
         end
+
+        self
       end
     end
 
@@ -225,6 +260,5 @@ def self.from_a(arr)
         ret
       end
     end
-
   end
 end