Modify HandleCommand to not do any argument processing until it has determined whether or
not the command should take raw input, then handle & dispatch the arguments appropriately.

Also change the 'alias' command to be a command that takes raw input.  This is necessary to
allow aliases to be created for other commands that take raw input and might want to include
raw input in the alias itself.

Fix a bug in the aliasing mechanism when creating aliases for commands with 3-or-more words.

Raw input should now be properly handled by all the command and alias mechanisms.

llvm-svn: 121423