Minor: Missing class descriptors

In debug mode I saw a bunch of missing descriptor errors, so I fixed it :)
Some more descriptor
Logout door icon for endusers

I got several complaint about the missing logout possibility for end users.
I disabled 'thin header check' so now there is the door icon.
Also marked the part that most likely hid the text link sometimes ago.
People! Any idea who and why did that?!
Added icons to the tree menu

I really missed them for some years by now... :)
(Only one is new, the others are copies of already used icons.)
Added user input sanitation
Added more

  Checked the code, class might be passed from user input. (And why not?..)
Created new closeallinput.c

Honestly, Im not fully sure if this is all it's functionality, but tried to make it as good as possible (even tried to get more info using a decompiler, saw nothing else, though).
However! Now it become 32/64bit dependant, depending on compiling system. Hm. This is true to all sources.
Merge pull request #76 from semirke/dev

Logout link for end users