updated from benmills remote master

Author: renewablejohn

plugin/vimux.vim

@@ -319,10 +319,14 @@ class TmuxSession
   end
 
   def _send_command(command, target, auto_return = true)
-    _run("send-keys -t #{target} \"#{command.gsub('"', '\"')}\"")
+    _run("send-keys -t #{target} \"#{_escape_command(command)}\"")
     _run("send-keys -t #{target} Enter") if auto_return
   end
 
+  def _escape_command(command)
+    command.gsub('"', '\"').gsub('$', '\$')
+  end
+
   def _run(command)
     `tmux #{command}`
   end