Function: abs

DOC_MSE_VERSION: since 0.3.7

--Usage--
> abs(some_number)

Returns the absolute value of a number.

--Parameters--
! Parameter	Type				Description
| @input@	[[type:int]] or [[type:double]]	Number to determine the absolute value of

--Examples--
> abs(1.5) == 1.5
> abs(-1)  == 1
