Bypass the gzip function that compress man files.

Index: waftools/man.py
--- waftools/man.py.orig
+++ waftools/man.py
@@ -29,11 +29,12 @@ def gzip_func(task):
         if outf:
             outf.close()
 
-Task.task_factory('man', gzip_func, color='BLUE')
 
 @feature('man')
 @before_method('process_source')
 def process_man(self):
+    def empty(x):
+        pass
     source = self.to_nodes(getattr(self, 'source', []))
     self.source = []
 
@@ -50,11 +51,7 @@ def process_man(self):
 
         out = self.path.find_or_declare(node.name + '.gz')
 
-        tsk = self.create_task('man')
-        tsk.set_inputs(node)
-        tsk.set_outputs(out)
-
-        self.bld.install_files('${MANDIR}/man%s' % s, out)
+        self.bld.install_files('${MANDIR}/man%s' % s, node)
 
 
 def configure(conf):
