Allow map_hyphen to work for application names

1. Handle hyphen -> underscore replacement of the app name early in map_app(), so the application can be identified and its routing rules used (if they exist).  Without this, the rewriter fails to find the application with the hyphen in place, and reverts to the default.

2. Disable underscore -> hyphen mapping of app name when creating static URLs, as they will be invalid paths

gluon/rewrite.py

@@ -878,7 +878,10 @@ class MapUrlIn(object):
         self.domain_application = None
         self.domain_controller = None
         self.domain_function = None
-        arg0 = self.harg0
+        if base.map_hyphen:
+            arg0 = self.harg0.replace('-', '_')
+        else:
+            arg0 = self.harg0
         if not base.exclusive_domain and base.applications and arg0 in base.applications:
             self.application = arg0
         elif not base.exclusive_domain and arg0 and not base.applications:
@@ -1256,9 +1259,9 @@ class MapUrlOut(object):
         "Builds a/c/f from components"
         acf = ''
         if self.map_hyphen:
-            self.application = self.application.replace('_', '-')
             self.controller = self.controller.replace('_', '-')
             if self.controller != 'static' and not self.controller.startswith('static/'):
+                self.application = self.application.replace('_', '-')
                 self.function = self.function.replace('_', '-')
         if not self.omit_application:
             acf += '/' + self.application