title: Magento Downloader hangs up while trying to install Mage_all_Latest
body: <p>i have installed a magento Version 1.9.1.0 since a few months, everything works fine.
  Since a few weeks i'm trying to update Magento via the package Mage_All_Latest via the Magento Downloader, but nothing happens. I tried it in the last weeks with Version 1.9.1.1 - and since today with the brand new 1.9.2.0 - doesn't matter which - it doesn't work.
  In the green status window it tells me "Checking dependencies of packages" - and that's it. No Error, no message - just nothing.
  I tried this multiple times, nothing is going on - for hours!
  The package is not in the /downloader/.cache-Directory.
  When trying to upgrade single packages manually via downloader it always tells me things like</p>
  
  <pre><code>CONNECT ERROR: Package community/Cm_RedisSession 1.9.2.0 conflicts with: community/Mage_All_Latest 1.9.1.0" - but i cannot update this package...!
  </code></pre>
  
  <p>There is enough space available on the server.
  The downloader itself has no problems - i tried to install all available packages in different relations and some worked:</p>
  
  <pre><code>Checking dependencies of packages
  Starting to download Lib_Varien-1.9.2.0.tgz ...
  ...done: 157,974 bytes
  Installing package community/Lib_Varien 1.9.2.0
  Package community/Lib_Varien 1.9.2.0 installed successfully
  </code></pre>
  
  <p>I cannot access the server via SSH.
  Is there any other option to upgrade this package? do i have to download the full new Magento installation package and override all files manually? or can i download this "Mage_all_latest"-Package on the magentocommerce-Website and replace all files manually? Is there any other option?
  Does anybody have an idea what to do?
  There is no error message :-(
  Thank you.</p>