fix: Remove all variables and most functions from global scope (#61)

To avoid name collisions on sites due to common names, e.g. Uncaught
SyntaxError: Identifier 'options' has already been declared

This also updates to use version 1.0.2 of trace-anything.

Changes have been formatted with Chromium's JavaScript formatter.

Fixes #44

content-script.js

@@ -16,28 +16,30 @@
  * @fileoverview Does necessary set up for the EME Logger extension.
  */
 
-// Load required scripts into the current web page.
-const urls = ['/trace-anything.js', '/eme-trace-config.js'];
-for (const url of urls) {
-  const absoluteUrl = chrome.runtime.getURL(url);
+(() => {
+  // Load required scripts into the current web page.
+  const urls = [ '/trace-anything.js', '/eme-trace-config.js' ];
+  for (const url of urls) {
+    const absoluteUrl = chrome.runtime.getURL(url);
 
-  // Insert a script tag and force it to load synchronously.
-  const script = document.createElement('script');
-  script.type = 'text/javascript';
-  script.defer = false;
-  script.async = false;
-  script.src = absoluteUrl;
-  (document.head || document.documentElement).appendChild(script);
-}
-
-// Listen for message events posted from eme-trace-config, then forward the
-// log to the log window.  If the log window is closed, this message gets
-// dropped.
-window.addEventListener('message', (event) => {
-  if (event.data.type == 'emeTraceLog') {
-    chrome.runtime.sendMessage({
-      type: 'EME_LOGGER_TRACE',
-      log: event.data.log,
-    });
+    // Insert a script tag and force it to load synchronously.
+    const script = document.createElement('script');
+    script.type = 'text/javascript';
+    script.defer = false;
+    script.async = false;
+    script.src = absoluteUrl;
+    (document.head || document.documentElement).appendChild(script);
   }
-});
+
+  // Listen for message events posted from eme-trace-config, then forward the
+  // log to the log window.  If the log window is closed, this message gets
+  // dropped.
+  window.addEventListener('message', (event) => {
+    if (event.data.type == 'emeTraceLog') {
+      chrome.runtime.sendMessage({
+        type : 'EME_LOGGER_TRACE',
+        log : event.data.log,
+      });
+    }
+  });
+})();