Added tag v18.11 for changeset dd8e950033d5
Created release v18.11
updated sourceforge links
Fixed another forum link
Fixed a compile time error that could happen when calling fft()
for certain input types.
Upgraded fft() and ifft() to support 2D matrices.
Fixed a compile time error that prevented auto_threshold_image() from being
used.
Merged in Patrick Snape's patch that allows the python bindings to
be built without GUI support.
Added an example showing how to use OpenCV's frame grabber
for face pose estimation.
updated docs
Increased min required cmake version to avoid warnings
from OpenCV cmake scripts.
Made extract_image_chips() much faster when extracting an unscaled and
unrotated chip.  Also added another constructor to chip_details that takes just
a rectangle.
Removed boost namespace to avoid name clashes with newer versions of boost.
Merged in code changes from MITIE project
merged