Treat Owners paths like "/src/backend" and "/src/backend/" identically

Summary:
Depends on D19183. Ref T11015. Currently, adding a trailing slash works great and omitting it mysteriously doesn't work.

Store a normalized version with an unconditional trailing slash for the lookup logic to operate on, and a separate display version which tracks what the user actually typed.

Test Plan:
  - Entered "/src/main.c", "/src/main.c/", saw them de-duplicate.
  - Entered "/src/main.c", saw it stay that way in the UI but appear as "/src/main.c/" internally.
  - Added a rule for "/src/applications/owners" (no slash), created a revision touching paths in that directory, saw Owners fire for it.
  - Changed the display value of a path only ("/src/main.c" to "/src/main.c/"), saw the update reflected in the UI without any beahvioral change.

Maniphest Tasks: T11015

Differential Revision: https://secure.phabricator.com/D19184

resources/celerity/map.php

@@ -424,7 +424,7 @@ return array(
     'rsrc/js/application/maniphest/behavior-line-chart.js' => 'e4232876',
     'rsrc/js/application/maniphest/behavior-list-edit.js' => 'a9f88de2',
     'rsrc/js/application/maniphest/behavior-subpriorityeditor.js' => '71237763',
-    'rsrc/js/application/owners/OwnersPathEditor.js' => 'aa1733d0',
+    'rsrc/js/application/owners/OwnersPathEditor.js' => '996d62b9',
     'rsrc/js/application/owners/owners-path-editor.js' => '7a68dda3',
     'rsrc/js/application/passphrase/passphrase-credential-control.js' => '3cb0b2fc',
     'rsrc/js/application/pholio/behavior-pholio-mock-edit.js' => 'bee502c8',
@@ -764,7 +764,7 @@ return array(
     'maniphest-task-edit-css' => 'fda62a9b',
     'maniphest-task-summary-css' => '11cc5344',
     'multirow-row-manager' => 'b5d57730',
-    'owners-path-editor' => 'aa1733d0',
+    'owners-path-editor' => '996d62b9',
     'owners-path-editor-css' => '2f00933b',
     'paste-css' => '9fcc9773',
     'path-typeahead' => 'f7fc67ec',
@@ -1676,6 +1676,14 @@ return array(
       'javelin-mask',
       'phabricator-drag-and-drop-file-upload',
     ),
+    '996d62b9' => array(
+      'multirow-row-manager',
+      'javelin-install',
+      'path-typeahead',
+      'javelin-dom',
+      'javelin-util',
+      'phabricator-prefab',
+    ),
     '9a6dd75c' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1766,14 +1774,6 @@ return array(
       'javelin-fx',
       'javelin-util',
     ),
-    'aa1733d0' => array(
-      'multirow-row-manager',
-      'javelin-install',
-      'path-typeahead',
-      'javelin-dom',
-      'javelin-util',
-      'phabricator-prefab',
-    ),
     'ab2f381b' => array(
       'javelin-request',
       'javelin-behavior',