Fixed yield of RMagic crop method.

RMagic should `crop!` with a bang!
MiniMagic `crop` method should `.apply(combine_options)`.
Fixed copy/paste error in MiniMagic `crop` method description.
Removed redundant blank line in MiniMagic & RMagic `crop` method descriptions.

lib/carrierwave/processing/mini_magick.rb

@@ -219,7 +219,6 @@ def resize_and_pad(width, height, background=:transparent, gravity='Center', com
     # by [width] and [height]. The original image bottom/right edge is preserved if the cropping box falls
     # outside the image bounds.
     #
-    #
     # === Parameters
     #
     # [left (integer)] left edge of area to extract
@@ -229,13 +228,14 @@ def resize_and_pad(width, height, background=:transparent, gravity='Center', com
     #
     # === Yields
     #
-    # [Magick::Image] additional manipulations to perform
+    # [MiniMagick::Image] additional manipulations to perform
     #
     def crop(left, top, width, height, combine_options: {}, &block)
       width, height = resolve_dimensions(width, height)
 
       minimagick!(block) do |builder|
         builder.crop(left, top, width, height)
+          .apply(combine_options)
       end
     end
 

lib/carrierwave/processing/rmagick.rb

@@ -269,7 +269,6 @@ def resize_to_geometry_string(geometry_string)
     # by [width] and [height]. The original image bottom/right edge is preserved if the cropping box falls
     # outside the image bounds.
     #
-    #
     # === Parameters
     #
     # [left (integer)] left edge of area to extract
@@ -286,7 +285,9 @@ def crop(left, top, width, height, combine_options: {})
       height = dimension_from height
 
       manipulate! do |img|
-        img.crop(left, top, width, height)
+        img.crop!(left, top, width, height)
+        img = yield(img) if block_given?
+        img
       end
     end