Move warning about directory not on sys.path to debug level.

Fix a bunch of multiline string constants that used +.
diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
index 746ca1f..322177f 100644
--- a/Lib/distutils/command/install.py
+++ b/Lib/distutils/command/install.py
@@ -2,6 +2,8 @@
 
 Implements the Distutils 'install' command."""
 
+from distutils import log
+
 # created 1999/03/13, Greg Ward
 
 __revision__ = "$Id$"
@@ -368,8 +370,8 @@
                 self.install_scripts is None or
                 self.install_data is None):
                 raise DistutilsOptionError, \
-                      "install-base or install-platbase supplied, but " + \
-                      "installation scheme is incomplete"
+                      ("install-base or install-platbase supplied, but "
+                      "installation scheme is incomplete")
             return
 
         if self.home is not None:
@@ -464,8 +466,8 @@
                 (path_file, extra_dirs) = self.extra_path
             else:
                 raise DistutilsOptionError, \
-                      "'extra_path' option must be a list, tuple, or " + \
-                      "comma-separated string with 1 or 2 elements"
+                      ("'extra_path' option must be a list, tuple, or "
+                      "comma-separated string with 1 or 2 elements")
 
             # convert to local form in case Unix notation used (as it
             # should be in setup scripts)
@@ -522,10 +524,10 @@
         if (self.warn_dir and
             not (self.path_file and self.install_path_file) and
             install_lib not in sys_path):
-            self.warn(("modules installed to '%s', which is not in " +
-                       "Python's module search path (sys.path) -- " +
-                       "you'll have to change the search path yourself") %
-                      self.install_lib)
+            log.debug(("modules installed to '%s', which is not in "
+                       "Python's module search path (sys.path) -- " 
+                       "you'll have to change the search path yourself"),
+                       self.install_lib)
 
     # run ()