Clean up error handling and reporting in "am".
Make the usage message for "am" more informative.
Make it easier to turn on logging in GoogleHttpClient.
The am command is now the one that takes care of opening the target file,
handling the opened file descriptor to the process that will be profiled.
This allows you to send profile data to anywhere the shell can access, and
avoids any problems coming up from the target process trying to open the
file.
Now we have a 5-second time after home is pressed, during which
only the home app (and the status bar) can switch to another app.
After that time, any start activity requests that occurred will
be executed, to allow things like alarms to be displayed. Also
if during that time the user launches another app, the pending
starts will be executed without resuming their activities and
the one they started placed at the top and executed.
