Added a heap of tests to test for: suppressinos using ';', command

interpolation etc, changed some `run ".blah"` commands to straight-up `system` (maybe
should change back?).

lib/pry/commands.rb

@@ -89,7 +89,7 @@ class Pry
     end
 
     command "ri", "View ri documentation. e.g `ri Array#each`" do |*args|
-      run target, ".ri", *args
+      system "ri", *args
     end
 
     command "stat", "View method information and set _file_ and _dir_ locals" do |*args|

test/test.rb

@@ -379,6 +379,30 @@ describe Pry do
         end
 
         describe "commands" do
+          it 'should interpolate ruby code into commands' do
+            klass = Class.new(Pry::CommandBase) do
+              command "hello", "", :keep_retval => true do |arg|
+                arg
+              end
+            end
+
+            $test_interpolation = "bing"
+            str_output = StringIO.new
+            Pry.new(:input => StringIO.new("hello #{$test_interpolation}"), :output => str_output, :commands => klass).rep
+            str_output.string.should =~ /bing/
+            $test_interpolation = nil
+          end
+
+          it 'should create a comand in  a nested context and that command should be accessible from the parent' do
+            str_input = StringIO.new("@x=nil\ncd 7\n_pry_.commands.instance_eval {\ncommand('bing') { |arg| run arg }\n}\ncd ..\nbing ls\nexit")
+            str_output = StringIO.new
+            Pry.input = str_input
+            obj = Object.new
+            Pry.new(:output => str_output).repl(obj)
+            Pry.input = Readline
+            str_output.string.should =~ /@x/
+          end
+
           it 'should define a command that keeps its return value' do
             class Command68 < Pry::CommandBase
               command "hello", "", :keep_retval => true do
@@ -500,7 +524,7 @@ describe Pry do
               end
 
               command "run_v" do
-                run target, "v"
+                run "v"
               end
             end