Fixed issue 04254: The user needs to delete or rename the installation directory after installation.
Dev This patch automatically deletes the install folder.
Dev If it is not possible due to permission issue, it will give an error message.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey@8556 b72ed6b6-b9f8-46b5-92b4-906544132732