started implementing pruning

We need to allow for nodes with only one child to get it working
Merge branch 'master' into pruning

Conflicts:
	src/Makefile.am
Enabled pruning also when using user params
started rewriting printForest()
Merge branch 'master' of github.com:paulstaab/scrm into pruning

Conflicts:
	src/scrm.cc
now assigns positions seperatly from printForest()
tree printing
new fancy tree printing method
added pruning for unneeded local nodes
fixed bugs; added command line option for pruning;
Merge branch 'pruning'

Conflicts:
	src/random/random_generator.cc
adapted makefile to include icsi_log