* - Refactored Complex Engineering Functions to use external complex number library
- Added calculation engine support for the new complex number functions that were added in MS Excel 2013
- IMCOSH() Returns the hyperbolic cosine of a complex number
- IMCOT() Returns the cotangent of a complex number
- IMCSC() Returns the cosecant of a complex number
- IMCSCH() Returns the hyperbolic cosecant of a complex number
- IMSEC() Returns the secant of a complex number
- IMSECH() Returns the hyperbolic secant of a complex number
- IMSINH() Returns the hyperbolic sine of a complex number
- IMTAN() Returns the tangent of a complex number
* Simplified the parseComplex() method in the PhpOffice\PhpSpreadsheet\Calculation\Engineering class, using Complex\Complex; and docblock flagged as deprecated