(core) Speed up and upgrade build.

Summary:
- Upgrades to build-related packages:
  - Upgrade typescript, related libraries and typings.
  - Upgrade webpack, eslint; add tsc-watch, node-dev, eslint_d.

- Build organization changes:
  - Build webpack from original typescript, transpiling only; with errors still
    reported by a background tsc watching process.

- Typescript-related changes:
  - Reduce imports of AWS dependencies (very noticeable speedup)
  - Avoid auto-loading global @types
  - Client code is now built with isolatedModules flag (for safe transpilation)
  - Use allowJs to avoid copying JS files manually.

- Linting changes
  - Enhance Arcanist ESLintLinter to run before/after commands, and set up to use eslint_d
  - Update eslint config, and include .eslintignore to avoid linting generated files.
  - Include a bunch of eslint-prompted and eslint-generated fixes
  - Add no-unused-expression rule to eslint, and fix a few warnings about it

- Other items:
  - Refactor cssInput to avoid circular dependency
  - Remove a bit of unused code, libraries, dependencies

Test Plan: No behavior changes, all existing tests pass. There are 30 tests fewer reported because `test_gpath.py` was removed (it's been unused for years)

Reviewers: paulfitz

Reviewed By: paulfitz

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D3498

app/client/ui/BillingPage.ts

@@ -236,7 +236,7 @@ export class BillingPage extends Disposable {
             moneyPlan?.amount ? [
               makeSummaryFeature([`Your team site has `, `${sub.userCount}`,
                 ` member${sub.userCount !== 1 ? 's' : ''}`]),
-              tier ? this._makeAppSumoFeature(discountName!) : null,
+              tier ? this._makeAppSumoFeature(discountName) : null,
               // Currently the subtotal is misleading and scary when tiers are in effect.
               // In this case, for now, just report what will be invoiced.
               !tier ? makeSummaryFeature([`Your ${moneyPlan.interval}ly subtotal is `,

app/client/ui/MakeCopyMenu.ts

@@ -6,6 +6,7 @@
 import {AppModel, reportError} from 'app/client/models/AppModel';
 import {getLoginOrSignupUrl, urlState} from 'app/client/models/gristUrlState';
 import {getWorkspaceInfo, ownerName, workspaceName} from 'app/client/models/WorkspaceInfo';
+import {cssInput} from 'app/client/ui/cssInput';
 import {bigBasicButton, bigPrimaryButtonLink} from 'app/client/ui2018/buttons';
 import {labeledSquareCheckbox} from 'app/client/ui2018/checkbox';
 import {colors, testId, vars} from 'app/client/ui2018/cssVars';
@@ -275,16 +276,6 @@ class SaveCopyModal extends Disposable {
   }
 }
 
-export const cssInput = styled('input', `
-  height: 30px;
-  width: 100%;
-  font-size: ${vars.mediumFontSize};
-  border-radius: 3px;
-  padding: 5px;
-  border: 1px solid ${colors.darkGrey};
-  outline: none;
-`);
-
 export const cssField = styled('div', `
   margin: 16px 0;
   display: flex;

app/client/ui/cssInput.ts

@@ -0,0 +1,12 @@
+import {colors, vars} from 'app/client/ui2018/cssVars';
+import {styled} from 'grainjs';
+
+export const cssInput = styled('input', `
+  height: 30px;
+  width: 100%;
+  font-size: ${vars.mediumFontSize};
+  border-radius: 3px;
+  padding: 5px;
+  border: 1px solid ${colors.darkGrey};
+  outline: none;
+`);

app/client/ui/transitions.ts

@@ -75,7 +75,7 @@ export function prepareForTransition(elem: HTMLElement, prepare: () => void) {
   // Recompute styles while transitions are off. See https://stackoverflow.com/a/16575811/328565
   // for explanation and https://stackoverflow.com/a/31862081/328565 for the recommendation used
   // here to trigger a style computation without a reflow.
-  window.getComputedStyle(elem).opacity;   // tslint:disable-line:no-unused-expression
+  window.getComputedStyle(elem).opacity;   // eslint-disable-line no-unused-expressions
 
   // Restore transitions.
   elem.style.transitionProperty = prior;