Cleanup dashboard JS (#491)

* Cleanup dashboard JS

* Add vscode

* Save start_mark/end_mark

* Updates

* Updates

* Remove need for cv.nameable

It's a bit hacky but removes so much bloat from integrations

* Add enum helper

* Document APIs, and Improvements

* Fixes

* Fixes

* Update PULL_REQUEST_TEMPLATE.md

* Updates

* Updates

* Updates

esphome/config_helpers.py

@@ -0,0 +1,27 @@
+from __future__ import print_function
+
+import codecs
+import json
+
+from esphome.core import CORE, EsphomeError
+from esphome.py_compat import safe_input
+
+
+def read_config_file(path):
+    # type: (basestring) -> unicode
+    if CORE.vscode:
+        print(json.dumps({
+            'type': 'read_file',
+            'path': path,
+        }))
+        data = json.loads(safe_input())
+        assert data['type'] == 'file_response'
+        return data['content']
+
+    try:
+        with codecs.open(path, encoding='utf-8') as handle:
+            return handle.read()
+    except IOError as exc:
+        raise EsphomeError(u"Error accessing file {}: {}".format(path, exc))
+    except UnicodeDecodeError as exc:
+        raise EsphomeError(u"Unable to read file {}: {}".format(path, exc))