Fix line comments syntax

Don't write parsers after midnight kids.

For the explanation: I mixed up the syntax bits between Blueprint and
textual protocol buffers...

src/grammar.json

@@ -21,12 +21,12 @@
         }
       ]
     },
-    "comment": {
+    "line_comment": {
       "type": "SEQ",
       "members": [
         {
           "type": "STRING",
-          "value": "#"
+          "value": "//"
         },
         {
           "type": "PATTERN",
@@ -935,7 +935,7 @@
     },
     {
       "type": "SYMBOL",
-      "name": "comment"
+      "name": "line_comment"
     }
   ],
   "conflicts": [],

src/node-types.json

@@ -172,11 +172,6 @@
     "named": true,
     "fields": {}
   },
-  {
-    "type": "comment",
-    "named": true,
-    "fields": {}
-  },
   {
     "type": "default_case",
     "named": true,
@@ -259,6 +254,11 @@
       ]
     }
   },
+  {
+    "type": "line_comment",
+    "named": true,
+    "fields": {}
+  },
   {
     "type": "list_expression",
     "named": true,
@@ -632,10 +632,6 @@
     "type": "\"",
     "named": false
   },
-  {
-    "type": "#",
-    "named": false
-  },
   {
     "type": "(",
     "named": false
@@ -652,6 +648,10 @@
     "type": "-",
     "named": false
   },
+  {
+    "type": "//",
+    "named": false
+  },
   {
     "type": ":",
     "named": false