src: added class method 'Complex.acos()'
test: added 'Complex.acos()' testing
readme: added 'Complex.acos()' api
src: added class method 'Complex.acosh()'
test: added 'Complex.acosh()' testing
readme: added 'Complex.acosh()' api
src: added class method 'Complex.asin()'
test: test 'Complex.asin()' testing
readme: added 'Complex.asin()' api
src: added class method 'Complex.asinh()'
test: added 'Complex.asinh()' testing
readme: added 'Complex.asinh()' api
src: added class method 'Complex.atan()'
test: added 'Complex.atan()' testing
readme: added 'Complex.atan()' api
src: added class method 'Complex.atanh()'
test: added 'Complex.atanh()' testing
readme: added 'Complex.atanh()' api