in the process of change scd
remove scd part, prepare for 0.7
remove convert to avoid confusion
Revert "remove scd part, prepare for 0.7"

This reverts commit 06421ffd51d248bdcd9403405c829fed3c0b4037.

Conflicts:
	bin/makefile
use ccv_minimize to do the logistic regression
create ccv_minimize_default_params
make sure the result is on-par with liblinear ones
support active set (weight trimming) in scd
fix two problems with scd doesn't resume properly
fix two more state resuming issues
change frequency of print outs
using a different loss function to see how that goes
change the way we do boosting to traditional gentle adaboost (rather than auc)
speed up backtracing removal
start to benchmark on fddb
removed liblinear dependency for ccv_scd
still very much work in progress for scd

The current plan is to mix scd feature with icf feature and have 3
cascade layers purely on scd feature (for faster process), and then a
soft-cascade layer with scd / icf feature. Acquired a 64GiB memory
desktop for this purpose.
refactor a bit and prepare to hybrid scd with icf
changed the struct for hybrid scd
commit a trained face model for now, and probably will release 0.7 with scd