json: implement {manifest} template

Property naming was borrowed from `hg files -Tjson`.

We omit branch because, again, representation of branches in this
template is wonky.

mercurial/templates/json/map

@@ -29,7 +29,27 b" changesetbranch = '{name|json}'"
 changesetbookmark = '{bookmark|json}'
 changesettag = '{tag|json}'
 changesetparent = '{node|json}'
-manifest = '"not yet implemented"'
+manifest = '\{
+  "node": {node|json},
+  "abspath": {path|json},
+  "directories": [{join(dentries%direntry, ", ")}],
+  "files": [{join(fentries%fileentry, ", ")}],
+  "bookmarks": [{join(bookmarks%name, ", ")}],
+  "tags": [{join(tags%name, ", ")}]
+  }'
+name = '{name|json}'
+direntry = '\{
+  "abspath": {path|json},
+  "basename": {basename|json},
+  "emptydirs": {emptydirs|json}
+  }'
+fileentry = '\{
+  "abspath": {file|json},
+  "basename": {basename|json},
+  "date": {date|json},
+  "size": {size|json},
+  "flags": {permissions|json}
+  }'
 tags = '\{
   "node": {node|json},
   "tags": [{join(entriesnotip%tagentry, ", ")}]

tests/test-hgweb-json.t

@@ -119,10 +119,46 b' file/{revision}/{path} shows file revisi'
 
 file/{revision} shows root directory info
 
-  $ request json-file/06e557f3edf6
+  $ request json-file/cc725e08502a
   200 Script output follows
   
-  "not yet implemented"
+  {
+    "abspath": "/",
+    "bookmarks": [],
+    "directories": [
+      {
+        "abspath": "/da",
+        "basename": "da",
+        "emptydirs": ""
+      }
+    ],
+    "files": [
+      {
+        "abspath": ".hgtags",
+        "basename": ".hgtags",
+        "date": [
+          0.0,
+          0
+        ],
+        "flags": "",
+        "size": 92
+      },
+      {
+        "abspath": "foo-new",
+        "basename": "foo-new",
+        "date": [
+          0.0,
+          0
+        ],
+        "flags": "",
+        "size": 4
+      }
+    ],
+    "node": "cc725e08502a79dd1eda913760fbe06ed7a9abc7",
+    "tags": [
+      "tip"
+    ]
+  }
 
 changelog/ shows information about several changesets
 
@@ -522,7 +558,31 b' manifest/{revision}/{path} shows info ab'
   $ request json-manifest/06e557f3edf6/
   200 Script output follows
   
-  "not yet implemented"
+  {
+    "abspath": "/",
+    "bookmarks": [],
+    "directories": [
+      {
+        "abspath": "/da",
+        "basename": "da",
+        "emptydirs": ""
+      }
+    ],
+    "files": [
+      {
+        "abspath": "foo",
+        "basename": "foo",
+        "date": [
+          0.0,
+          0
+        ],
+        "flags": "",
+        "size": 4
+      }
+    ],
+    "node": "06e557f3edf66faa1ccaba5dd8c203c21cc79f1e",
+    "tags": []
+  }
 
 tags/ shows tags info