Paste over selection / And <Alt-o> for normal mode

So when you paste something and there's an active selection of text then
the selection is replaced by that which is pasted.

Also, includes <Alt-o> for normal mode shortcut to `:`

1 files changed, 16 insertions, 1 deletions

diff --git a/spec/novim_mode_spec.rb b/spec/novim_mode_spec.rb
index b960b10..0b99674 100644
--- a/spec/novim_mode_spec.rb
+++ b/spec/novim_mode_spec.rb
@@ -66,13 +66,28 @@ describe 'Basic editing' do
       select me
     EOF
 
-    # Conventional behaviour shouldn't need the <End>?
     type '<C-a>gone'
 
     after <<-EOF
       gone
     EOF
   end
+
+  specify 'paste over selection' do
+    before <<-EOF
+      cut me and paste over me
+    EOF
+
+    7.times { type '<S-Right>' }
+    type '<C-x>'
+    10.times { type '<Right>' }
+    7.times { type '<S-Right>' }
+    type '<C-v>'
+
+    after <<-EOF
+      and paste cut me
+    EOF
+  end
 end
 
 describe 'Pane control' do