Major refactor -- split windows into separate files

main/power-save-blocker.js

@@ -0,0 +1,25 @@
+module.exports = {
+  start,
+  stop
+}
+
+var electron = require('electron')
+var log = require('./log')
+
+var powerSaveBlockerId = 0
+
+function start () {
+  // Stop the previous power saver block, if one exists.
+  stop()
+
+  powerSaveBlockerId = electron.powerSaveBlocker.start('prevent-display-sleep')
+  log('powerSaveBlocker.start %d', powerSaveBlockerId)
+}
+
+function stop () {
+  if (!electron.powerSaveBlocker.isStarted(powerSaveBlockerId)) {
+    return
+  }
+  electron.powerSaveBlocker.stop(powerSaveBlockerId)
+  log('powerSaveBlocker.stop %d', powerSaveBlockerId)
+}