ClosedXML 0.89.0

https://github.com/ClosedXML/ClosedXML/issues?q=is%3Aissue+milestone%3Av0.89+is%3Aclosed

• #477 Merge pull request #477 from igitur/issue476-unhide-sheet (@igitur)
• #467 Merge pull request #467 from igitur/fix-pivot-table-saving (@igitur)
• #466 Merge pull request #466 from igitur/fix-phonetics (@igitur)
• #462 Merge pull request #462 from igitur/update-source-after-saveas (@igitur)
• #443 Merge pull request #443 from igitur/optimize-calcchain-generation (@igitur)
• #455 Merge pull request #455 from igitur/fix-warnings (@igitur)
• #452 Merge pull request #452 from igitur/issue447-delete-columns-from-table (@igitur)
• #445 Merge pull request #445 from igitur/issue444-duplicate-image-name-exception (@igitur)
• #400 Merge pull request #400 from igitur/create-xlworkbook-from-template (@igitur)
• #448 Merge pull request #448 from igitur/issue446-rename-worksheet-change-case (@igitur)
• #440 Merge pull request #440 from igitur/allow-formulae-that-start-with-equals-plus (@igitur)
• #439 Merge pull request #439 from igitur/issue438-vlookup-bad-expression (@igitur)
• #412 Merge pull request #412 from igitur/issue410-load-table-without-name (@igitur)
• #437 Merge pull request #437 from igitur/issue435-nullreferenceexception-on-multiple-save (@igitur)
• #429 Merge pull request #429 from igitur/issue424-null-reference-exception-when-loading-defined-name (@igitur)
• #423 Merge pull request #423 from igitur/issue422-set-null-value (@igitur)
• #418 Merge pull request #418 from igitur/issue416-named-range-bug-when-copying-worksheet (@igitur)
• #409 Merge pull request #409 from igitur/support-functions-with-period (@igitur)
• #408 Merge pull request #408 from igitur/issue285-update-table-fieldnames (@igitur)
• #407 Merge pull request #407 from igitur/issue346-correctly-implement-mod-function (@igitur)
• #406 Merge pull request #406 from igitur/issue347-floor-function-parameters (@igitur)
• #403 Merge pull request #403 from igitur/issue352-clear-row-height-and-column-width (@igitur)
• #402 Merge pull request #402 from igitur/issue350-Inserting-rows-causes-changes-of-rows-heights (@igitur)
• #399 Merge pull request #399 from igitur/find-string-helper-functions (@igitur)
• #398 Merge pull request #398 from igitur/insert-data-horizontally (@igitur)
• #394 Merge pull request #394 from igitur/databar-conditional-formatting (@igitur)
• #393 Merge pull request #393 from igitur/issue392-ArgumentOutOfRangeException (@igitur)
• #390 Merge pull request #390 from igitur/hide-pivot-table-subtotals (@igitur)
• #235 Merge pull request #235 from aakasaka/develop (@aakasaka)
• #442 Merge pull request #442 from igitur/remove-IsNullOrWhiteSpace-net35-workaround (@igitur)
• #256 Merge pull request #256 from ClosedXML/develop (@igitur, @b0bi79, @togakangaroo, @vbjay, @clinchergt, @wtetsu, @bsermons, @pdennis33, @nomomax, @Golans)