Fix some imports and other checker warnings

* Removed a number of imports reported as unused.
* Reorganize imports in a few places.
* Checker reported warnings problems ("Instantiating an exception,
  but not raising it, has no effect"): serveral tool modules instantiated
  a warning class thinking (?) it would issue the warning; changed these to
  the standard use - calling the warn() function with the warnclass as an arg.
* Tool modules that were touched had the copyright header munging applied.
* Removed irritating "####" lines from gettext and msgfmt tools.

Signed-off-by: Mats Wichmann <mats@linux.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/SCons/Executor.py b/SCons/Executor.py
index ee52151..492ebe3 100644
--- a/SCons/Executor.py
+++ b/SCons/Executor.py
@@ -25,12 +25,12 @@
 
 import collections
 
-import SCons.Debug
-from SCons.Debug import logInstanceCreation
 import SCons.Errors
 import SCons.Memoize
 import SCons.Util
 from SCons.compat import NoSlotsPyPy
+import SCons.Debug
+from SCons.Debug import logInstanceCreation
 
 class Batch:
     """Remembers exact association between targets
@@ -270,10 +270,8 @@ class Executor(object, metaclass=NoSlotsPyPy):
         return self.get_lvars()[targets_string]
 
     def set_action_list(self, action):
-        import SCons.Util
         if not SCons.Util.is_List(action):
             if not action:
-                import SCons.Errors
                 raise SCons.Errors.UserError("Executor must have an action.")
             action = [action]
         self.action_list = action