Adding dotkit support to TAU.

- New spack.hooks package
  - contains modules with pre and post install hooks

- New dotkit hook module
  - generates/removes dotkits on install/uninstall

- New spack use, spack unuse commands
  - use same syntax as install/uninstall

- New setup-env.bash script
  - Sets up path, dotkit support

- new spack dotkit command
  - used by script to parse specs, generate
    specs of installed pckages for dotkit file names

lib/spack/llnl/util/tty/__init__.py

@@ -51,12 +51,14 @@ def msg(message, *args):
 
 def info(message, *args, **kwargs):
     format = kwargs.get('format', '*b')
-    cprint("@%s{==>} %s" % (format, cescape(str(message))))
+    stream = kwargs.get('stream', sys.stdout)
+
+    cprint("@%s{==>} %s" % (format, cescape(str(message))), stream=stream)
     for arg in args:
         lines = textwrap.wrap(
             str(arg), initial_indent=indent, subsequent_indent=indent)
         for line in lines:
-            print line
+            stream.write(line + '\n')
 
 
 def verbose(message, *args):
@@ -66,15 +68,15 @@ def verbose(message, *args):
 
 def debug(message, *args):
     if _debug:
-        info(message, *args, format='g')
+        info(message, *args, format='g', stream=sys.stderr)
 
 
 def error(message, *args):
-    info("Error: " + str(message), *args, format='*r')
+    info("Error: " + str(message), *args, format='*r', stream=sys.stderr)
 
 
 def warn(message, *args):
-    info("Warning: " + str(message), *args, format='*Y')
+    info("Warning: " + str(message), *args, format='*Y', stream=sys.stderr)
 
 
 def die(message, *args):