Small help text fixes, to make it more consistent and accurate.

Temporarily remove -l option from 'expr' command (at Sean's request).

llvm-svn: 113298
diff --git a/lldb/source/Commands/CommandObjectHelp.cpp b/lldb/source/Commands/CommandObjectHelp.cpp
index cf80cd4..a2959af 100644
--- a/lldb/source/Commands/CommandObjectHelp.cpp
+++ b/lldb/source/Commands/CommandObjectHelp.cpp
@@ -27,7 +27,7 @@
 
 CommandObjectHelp::CommandObjectHelp () :
     CommandObject ("help",
-                   "Shows a list of all debugger commands, or give details about specific commands.",
+                   "Show a list of all debugger commands, or give details about specific commands.",
                    "help [<cmd-name>]")
 {
 }