Fix remove_#{column}! doesn't remove the file immediately

Also the call to write_#{column}_identifier doesn't need to be in CarrierWave::ActiveRecord, since what it does is not specific to ActiveRecord.
Fixes #2540

lib/carrierwave/mount.rb

@@ -419,6 +419,8 @@ def remove_#{column}
 
         def remove_#{column}!
           _mounter(:#{column}).remove!
+          self.remove_#{column} = true
+          write_#{column}_identifier
         end
 
         def remove_#{column}=(value)

lib/carrierwave/mounter.rb

@@ -117,10 +117,11 @@ def remove?
 
     def remove!
       uploaders.reject(&:blank?).each(&:remove!)
-      @uploaders = []
+      clear!
     end
 
     def clear!
+      @remove = nil
       @uploaders = []
     end
 

lib/carrierwave/orm/activerecord.rb

@@ -85,13 +85,6 @@ def remove_#{column}=(value)
           result
         end
 
-        def remove_#{column}!
-          self.remove_#{column} = true
-          write_#{column}_identifier
-          self.remove_#{column} = false
-          super
-        end
-
         # Reset cached mounter on record reload
         def reload(*)
           @_mounters = nil

spec/orm/activerecord_spec.rb

@@ -475,6 +475,13 @@ def monkey
         @event.save!
       end
 
+      it "should remove the file immediately" do
+        file = @event.image.file
+        @event.remove_image!
+
+        expect(file).not_to exist
+      end
+
       it "should clear the serialization column" do
         @event.remove_image!
 
@@ -499,6 +506,16 @@ def monkey
         @event.remove_image = "1"
         expect(@event.image_changed?).to be_truthy
       end
+
+      it "resets remove_image? to false on save" do
+        @event.remove_image = true
+
+        expect {
+          @event.save!
+        }.to change {
+          @event.remove_image?
+        }.from(true).to(false)
+      end
     end
 
     describe "#remote_image_url=" do
@@ -1282,18 +1299,25 @@ def monkey
       before do
         @event.images = [stub_file('test.jpeg')]
         @event.save!
-        @event.remove_images!
       end
 
       it "should clear the serialization column" do
+        @event.remove_images!
         expect(@event.attributes['images']).to be_blank
       end
 
-      it "should return to false after being saved" do
-        @event.save!
-        expect(@event.remove_images).to eq(false)
+      it "should return to false" do
+        @event.remove_images!
+        expect(@event.remove_images).to be_falsy
         expect(@event.remove_images?).to eq(false)
       end
+
+      it "should remove the file immediately" do
+        file = @event.images.first.file
+        @event.remove_images!
+
+        expect(file).not_to exist
+      end
     end
 
     describe "remove_images=" do
@@ -1310,6 +1334,16 @@ def monkey
         @event.remove_images = "false"
         expect(@event.images_changed?).to be_falsey
       end
+
+      it "resets remove_images? to false on save" do
+        @event.remove_images = true
+
+        expect {
+          @event.save!
+        }.to change {
+          @event.remove_images?
+        }.from(true).to(false)
+      end
     end
 
     describe "#remote_images_urls=" do