Update 4.4DEV6

A first potencial relase candidate for mDOS 4.4 version. This update contains some bug fixes and code improvements.

• user list file was moved to system directory
• removed useless temp files

Fixed bugs

• the user list was not refreshed correctly after creating the first user.
• mDOS crashed after a fresh installation.
• system calls were active all the time since startup.
• User Account Control did not work correctly when the selected administrator account had a password.