Statistical issues (#1098)

* Merge branch 'master' of C:\Projects\PHPOffice\PHPSpreadsheet\develop with conflicts.

* Adjusted logic for COUNT() function to handle differences in EXCEL, GNUMERIC and OPENOFFICE modes for cells and for literal values

* Fix case-sensitivity in filenames

* Appeasing Codesniffer

* Resolve COUNTA() differences between cell values and literals

* Style fixes

* Start refactoring statistical function tests into individual tests rather than having a single, giant test for all statistical functions.... first step toward doing this for all tests

* More refactoring into separate tests
If all functions have their own individual test files, it should be a lot easier to identify which functions aren't covered by tests yet

* Missing last lines in files

tests/PhpSpreadsheetTests/Calculation/Functions/Statistical/BetaDistTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Calculation\Functions\Statistical;
+
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Calculation\Statistical;
+use PHPUnit\Framework\TestCase;
+
+class BetaDistTest extends TestCase
+{
+    public function setUp()
+    {
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
+    }
+
+    /**
+     * @dataProvider providerBETADIST
+     *
+     * @param mixed $expectedResult
+     */
+    public function testBETADIST($expectedResult, ...$args)
+    {
+        $result = Statistical::BETADIST(...$args);
+        self::assertEquals($expectedResult, $result, '', 1E-12);
+    }
+
+    public function providerBETADIST()
+    {
+        return require 'data/Calculation/Statistical/BETADIST.php';
+    }
+}