Value live_after() is a special case of the checks performed in
values_interfere(). This commit extracts this code and use the new function
where possible.

We query liveness from the irg on demand now.

Move the values interfere function to belive.h, move the inline
implementation into belive.c

It has been empty for nearly all systems. People who used to put stuff
in config.h can still create a config.h on their own and inject
-include (gcc) or /FI (msvc) into their CPPFLAGS.

Just state the copyright and the project the files belong to. You can
then find the COPYING file for the whole project.

Simply check, whether any liveness bits were set before.

- some code cleanup
- avoids the case where 2 dumpers are registered

- save ir_node* instead of irn_idx in the map (saves irn_idx_map
  lookups)
- in liveness_transfer check register class on the inputs (which is
  cheaper) and only then check the operand

The operation we want to perform is to get the live values just before a node.

This also plugs liveness related memory leaks