solve the sdk rename problem

I had the same problem: the latest update failed to install because it couldn't
rename the tools folder in android-sdk-windows.  I'm using Avira antivirus and
disabling it didn't help, but I don't think it had anything to do with the AV program
anyway.

Fact is, running the Android SDK setup apparently uses items in the
"android-sdk-windows\tools" directory.  I'm on Win 7 x64 so maybe that causes some
unique situation - I'm not sure.

Solution:

- I made a copy of the tools folder itself (keeping it at the same directory tree
level, thus "tools" and "tools-copy" were both in the "android-sdk-windows" folder).

- I ran Android.bat from that copy

- I ran the update without problems (it updated the original,
not-being-used-at-the-moment tools folder, among whatever other items it needed to).

- I closed the SDK, deleted the folder (I had to kill the adb.exe process first - not
sure why that always persists but you can't delete the folder without doing that).

- I restarted the SDK from the normal (now-updated) tools folder.  Worked like a charm!

Note that simply killing adb.exe was NOT sufficient to get around the original
issue... only by copying the tools folder and using the copy to run Android for the
duration of the update process was enough to rectify the problem.

I hope this helps others... it's quite vexing to have to spend time resolving basic
issues like this just to run an update.