Memory leak and some bugs

[leochangzliao]

For some images, if its height or width less than 32*4 pixels, this line

edgeBoxes-Cpp-version/src/edgesDetect.cpp

Line 54 in 288c4a6

const int h1 = (int) ceil(double(rowsiz - imWidth) / stride);

will be negative, and this line will break down.
My computer will not respond if I run the code many times, and it seems that all my CPU memory used up.