New class slipit threshold

Class duoc dung de tach nguong tu dong anh van tay, chuyen anh da muc xam
thanh anh 2 muc xam [0,255]
 On branch SplitThreshold
	new file:   RecognitionFingerprint/src/com/vnexit/fingerprint/datamodel/SplitThreshold.java
Fix split threshold

- Can phai chuyen anh sang anh gray truoc khi tien hanh tach nguong
 On branch SplitThreshold
	modified:   RecognitionFingerprint/src/com/vnexit/fingerprint/datamodel/SplitThreshold.java
	modified:   RecognitionFingerprint/src/com/vnexit/fingerprint/form/Fom.java
	modified:   RecognitionFingerprint/src/com/vnexit/fingerprint/gaborfilter/GaborFilter.java
Fix gabor filler

Bo loc gabor kem hieu qua voi anh dinh dang png, bo loc gabor hieu qua hon voi anh .jpg va .bmp
Fix cong thuc tinh huong garadien cua diem anh

Theo ly thuyet gia tri G = Gxx*Gyy tuy nhien thuc nghiem lai cho thay neu G = Gxx - Gyy thi ket qua anh tot hon
Merge branch 'SplitThreshold' into develop