* Fix Unintential Deprecated Calls in Tests - STATISTICAL
I think it's best to install these before PR #3166. There are no changes to source code, only to doc-blocks and to test members which continue to inadvertently use calls to deprecated functions.
* Missed One Deprecation
Fix it now.
* Run Tests in Spreadsheet Context
This is quite a bit more difficult for Statistical than for the other Calculation categories. This is partly because of the use of multi-dimensional matrices, and also because some arguments are interpreted differently when they come from a cell rather than entered directly in a formula. This push leaves 18 out of 89 test members unchanged, except that they are marked with a TODO to show that the work isn't finished. I will not revisit them as part of this PR, but probably will take a look in a subsequent ticket.
* Extract Permutation functions from the Statistical class into a dedicated Permutations class
Retain the original methods in the Statistical class as stubs for BC, but deprecate them. They will be removed for PHPSpreadsheet v2
Note that unit tests still point to the Statistical class stubs; these should be modified to use the Permutations class directly when the stubs are removed
Also provided a basic implementationof the PERMUTATIONA() Function
oleibman
Mark Baker
Adrien Crivelli