(core) Update ACL resources/rules when tables/columns get renamed

Summary:
- Placed rule-updating functions in acl.py.
- Reset UI when rules update externally, or alert the user to reset if there
  are pending local changes.
- Removed some unused and distracting bits from client-side DocModel.

A few improvements related to poor error handling:
- In case of missing DocActions (tickled by broken ACL rule handling), don't
  add to confusion by attempting to process bad actions
- In case of missing attributes in ACL formulas, return undefined rather than
  fail; the latter creates more problems.
- In case in invalid rules, fail rather than skip; this feels more correct now
  that we have error checking and recovery option, and helps avoid invalid rules.
- Prevent saving invalid rules with an empty ACL formula.
- Fix bug with rule positions.

Test Plan: Added a python and browser test for table/column renames.

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D2698

app/client/models/BaseRowModel.js

@@ -119,10 +119,12 @@ BaseRowModel.prototype._process_RenameColumn = function(action, tableId, oldColI
   // handle standard renames differently
   if (this._fields.indexOf(newColId) !== -1) {
     console.error("RowModel #RenameColumn %s %s %s: already exists", tableId, oldColId, newColId);
+    return;
   }
   var index = this._fields.indexOf(oldColId);
   if (index === -1) {
     console.error("RowModel #RenameColumn %s %s %s: not found", tableId, oldColId, newColId);
+    return;
   }
   this._fields[index] = newColId;