removed code for create_Pop: need to be reimplemented

added some needed callbacks

Earlier, that Proj was used by the IncSP
now, there is only a dependency edge

Adapted to the new dependency edges

revert commit that placed consts in startblock, the old code did an equally good job (though a bit slower) and avoided placing consts into the prologe

  of a mort smart placement
- (Also forgot to mention in my last committ that I fixed a bug that sometimes
  produced double spills in the morgan spiller)

- Cleanup remat code a little bit
- Adjust remat cost limit to new costs in ia32 backend
- Don't spill unused livethroughs around blocks anymore in bespill_morgan
  (but only around loops), this makes the code faster smaller and the results
  slightly better as belady performs better for basic blocks

 - Constants for SSE minus and ABS must be of mode Iu and Lu instead od F and D ...

 - x87_fpop now has NO argument (ra verifier fails otherwise due to wrong
   live time)

 - fcom set the wrong register

Added support for floating point Perm
Added preliminary suport for the "unknown reg" to be_Copy