Renamed numerical integration header to dlib/numerical_integration.h.  Changed relevant headers to include numerical_integration.h  Fixed documentation in integrate_function_adapt_simpson_abstract.h

Need to add documentation next.

Simpson rule.  Added unit tests and supporting examples for this
function.

which could occur when NaN valued inputs were given.

python.

the dlib GUI was used.

Simpson rule.  Added unit tests and supporting examples for this
function.

geometry components use the optimization tools.

from the non-negative feature learning range.  This change fixes that.

should help catch the case where a user changes the feature extractor and then
tries to load an old model.

to make the overall rectangle API more uniform.

a user to read the state of these objects.