less ugly mapdims

replaced the mapdims array with a struct with properly identified members

also reduced the calclight postfilter to actually used map areas
add attr5..7, add mapmodel pitch and roll

Keys 5, 6 and 7 (in combination with the scrollwheel) can be used to alter
the new entity attributes.

Pressing editmeta (LCTRL by default) speeds up the scrolling.

(Parts of the roll code are borrowed from Alejandro V. Garcia's commit
"Model rotations, experimental" from January 2013)