replicating readline control characters in test output

Readline is awful and dumps characters in the output.
This was causing tests to act weird on another build.

hphp/test/quick/debugger/flow.php.expectf

@@ -2,7 +2,7 @@ Welcome to HipHop Debugger!
 Type "help" or "?" for a complete list of commands.
 
 Program %s/flow.php loaded. Type '[r]un' or '[c]ontinue' to go.
-hphpd> break cls::pub()
+%Shphpd> break cls::pub()
 Breakpoint 1 set upon entering cls::pub()
 hphpd> run
 flow_t.php loaded

hphp/test/quick/debugger/flow2.php.expectf

@@ -2,7 +2,7 @@ Welcome to HipHop Debugger!
 Type "help" or "?" for a complete list of commands.
 
 Program %s/flow2.php loaded. Type '[r]un' or '[c]ontinue' to go.
-hphpd> run
+%Shphpd> run
 flow2.php done
 Program %s/flow2.php exited normally.
 hphpd> break test()

hphp/test/quick/debugger/flow_gen.php.expectf

@@ -2,7 +2,7 @@ Welcome to HipHop Debugger!
 Type "help" or "?" for a complete list of commands.
 
 Program %s/flow_gen.php loaded. Type '[r]un' or '[c]ontinue' to go.
-hphpd> run
+%Shphpd> run
 flow_gen.php loaded
 Program %s/flow_gen.php exited normally.
 hphpd> break flow_gen.php:12

hphp/test/quick/debugger/printThis.php.expectf

@@ -2,7 +2,7 @@ Welcome to HipHop Debugger!
 Type "help" or "?" for a complete list of commands.
 
 Program %sprintThis.php loaded. Type '[r]un' or '[c]ontinue' to go.
-hphpd> break printThis.php:5
+%Shphpd> break printThis.php:5
 Breakpoint 1 set on line 5 of printThis.php
 hphpd> run
 Breakpoint 1 reached at Foo::method() on line 5 of %sprintThis.php