Cleanups (#3742)

* Remove unused file

* Combine tx checks into single file

* Move UI components into UI

* DRY links

* Unused rollup config

* Cleanup util paths

* Revert "Move UI components into UI"

This reverts commit 3379e61246cde635c296d31322b71e63395a5cd4.

* Re-apply ~/util/tx move

* Cleanup unused styles

js/src/jsonrpc/rollup.config.js

@@ -1,12 +0,0 @@
-import babel from 'rollup-plugin-babel';
-
-export default {
-  entry: 'src/index.js',
-  dest: 'release/index.js',
-  format: 'cjs',
-  plugins: [babel({
-    babelrc: false,
-    presets: ['es2015-rollup', 'stage-0'],
-    runtimeHelpers: true
-  })]
-};