Log Message:
(math/nlopt)  Updated 2.4.2 to 2.6.2

# NLopt Release Notes

## NLopt 2.6.2

15 April 2020

* Fixed forced stop exception with dimension elimination ([#317])

* Fixed `get_initial_step` wrapping ([#319])

* Various build fixes ([#314], [#308], [#303], [#278])

## NLopt 2.6.1

13 April 2019

* Fix `nlopt_version` result for 2.6.x and update soname.

## NLopt 2.6

12 April 2019

* New `nlopt_set_upper_bound` and `nlopt_set_lower_bound` functions in the \ 
low-level C API to set one bound at a time ([#257]).

* There is no longer a separate `libnlopt_cxx` library: C++ algorithms (STOGO \ 
and AGS) are compiled and included by default ([#198]).

* Various build fixes ([#197], [#216], [#245], [#250], [#230], [#261], etc.), \ 
other fixes ([#242], [#258]).

## NLopt 2.5

26 July 2018

* New AGS global solver ([#194]), thanks to Vladislav Sovrasov.

* New `nlopt_get_numevals` function providing a built-in evaluation counter ([#160]).

* New `nlopt_get_errmsg` function for more descriptive error messages.

* Build system is converted to `cmake` ([#49]), thanks to Julien Schueller

* Plugins updated for recent Octave and Guile versions.

* Various other build fixes and minor bug fixes.