added a trace mode for tagger and parser. added confidence measure for perceptron.

maca_tools/src/mcf2conll.c

maca_trans_parser/CMakeLists.txt

maca_trans_parser/src/compare_traces.c

maca_trans_parser/src/config.c

maca_trans_parser/src/context.c

maca_trans_parser/src/context.h

maca_trans_parser/src/maca_trans_parser_arc_eager_mcf2cff.c

maca_trans_parser/src/simple_decoder_parser_arc_eager.c

perceptron/exec/CMakeLists.txt

perceptron/exec/cff_cutoff.c

perceptron/lib/src/feature_table.c