[TYPO3-hci] Better differentiated icons for read-only filemounts and folders in t3skin

[Steffen Kamper]

Hi Francois,

i would prefer the light grey ones as red implicits something "not 
allowed". This is not correct in this syntax as you are allowed to 
browse them and use for link, the only thing that isn't allowed is the 
upload.

vg Steffen