Remove all deprecated things about phpspreadsheet

[PowerKiKi]

This issue is specifically for already deprecated things that need to be dropped before the first release. We are beyond the deprecating phase (by several years in some cases). While I agree with you for future deprecations, I don't think it applies here.

[PowerKiKi]

Following the lack of input from @MarkBaker I took the iniative to un-deprecate those last few methods.

[Quix0r]

This might be a clear way of deprecation:

1. mark the method or code block as @deprecated and document a replacement
2. after x time-unit (e.g. 1/2 year?) remove the deprecated code

[PowerKiKi]

@MarkBaker I worked on removing deprecated methods and documenting their replacements.

But I got stuck on getCalculatedValue(), setFormulaAttributes() and setFormulaAttributes(), because I couldn't find any replacement. They've been deprecated in 59932b0 and the changelog mention that replacements will be added in the future, but it seems that it's never been done. It seems that everything is related to PHPOffice/PHPExcel#9. Is it still something that you are working on ? What should we do about getCalculatedValue() ?

[Quix0r]

getCalculatedValue() seems to be intensively used by PHPSpreadsheet: https://github.com/PHPOffice/PhpSpreadsheet/search?q=getCalculatedValue&type=Code&utf8=%E2%9C%93