Minor bugfixes and improvement

- Added mtedit --login to force re-authentication in case of issues
- use hidden form values when sending authentication
- small fix in log.py that prevented feedback logs from being properly
  extracted
- allow force_platform for trimming evdev files in mtreplay

BUG=chromium:361758
TEST=None

Change-Id: I467ae79e8aed5357c51be6cbb6c82e97cefd2ba0
Reviewed-on: https://chromium-review.googlesource.com/195609
Reviewed-by: Dennis Kempin <denniskempin@chromium.org>
Commit-Queue: Dennis Kempin <denniskempin@chromium.org>
Tested-by: Dennis Kempin <denniskempin@chromium.org>
diff --git a/mtlib/log.py b/mtlib/log.py
index 568e59a..552f2a2 100644
--- a/mtlib/log.py
+++ b/mtlib/log.py
@@ -130,13 +130,14 @@
     else:
       self.downloader = FeedbackDownloader()
       self.report = self.downloader.DownloadSystemLog(id_or_filename)
-      if self.report:
-        self._ExtractSystemLog()
-      if self.system:
-        self._ExtractLogFiles()
       if self.try_screenshot:
         self.image = self.downloader.DownloadScreenshot(id_or_filename)
 
+    if self.report:
+      self._ExtractSystemLog()
+    if self.system:
+      self._ExtractLogFiles()
+
     # Only write to screenshot.jpg if we will be viewing the screenshot
     if options and not options.download and self.image:
       file(screenshot_filepath, 'w').write(self.image)
@@ -291,3 +292,4 @@
     self.activity = self.remote.Read('/var/log/xorg/touchpad_activity_log.txt')
     self.evdev = self.remote.Read('/var/log/xorg/cmt_input_events.dat')
     self.system = ''
+    self.image = None