Shift selection of debug-level
Shift selection of debug-level

Currently configure switches on gcc to debug mode what means -O0. Adding
-d none does not help because it is filtered out earlier. -d bla would
help if bla were an allowed keyword.
This patch simply shifts the "compiler is gcc" block to the left so -O2 is
selected if the user selected -d none on the command line. Other compilers
remain with no extra switches.

OoberMick/Midori,OoberMick/Midori