Issue CollaboraOnline#43: Add customized phpcs.xml that passes.

phpcs.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ruleset name="DrupalCollaboraOnline">
+  <description>Modified PHP CodeSniffer configuration based on Drupal.</description>
+
+  <arg name="extensions" value="inc,install,module,php,theme,yml,json"/>
+
+  <exclude-pattern>./vendor/*</exclude-pattern>
+  <exclude-pattern>./web/*</exclude-pattern>
+  <file>.</file>
+
+  <rule ref="vendor/drupal/coder/coder_sniffer/Drupal/ruleset.xml">
+    <!-- Accept 4 spaces of indentation for now. -->
+    <exclude name="Drupal.WhiteSpace.ScopeIndent"/>
+    <exclude name="Drupal.Arrays.Array.ArrayIndentation"/>
+    <exclude name="Drupal.Functions.MultiLineFunctionDeclaration.Indent"/>
+    <exclude name="Drupal.WhiteSpace.ScopeClosingBrace.BreakIndent"/>
+    <exclude name="Drupal.WhiteSpace.ScopeClosingBrace.Indent"/>
+    <exclude name="Drupal.WhiteSpace.ObjectOperatorIndent.Indent"/>
+    <!-- Accept file doc comment with copyright. -->
+    <exclude name="Drupal.Commenting.FileComment.NamespaceNoFileDoc"/>
+    <exclude name="Drupal.Commenting.FileComment.WrongStyle"/>
+    <!-- Accept imports order from PhpStorm. -->
+    <exclude name="SlevomatCodingStandard.Namespaces.AlphabeticallySortedUses.IncorrectlyOrderedUses"/>
+    <!-- Keep existing identifiers, as renaming would be disruptive. -->
+    <exclude name="Drupal.NamingConventions.ValidFunctionName.InvalidName"/>
+    <exclude name="Drupal.NamingConventions.ValidVariableName.LowerCamelName"/>
+    <exclude name="Drupal.NamingConventions.ValidFunctionName.ScopeNotCamelCaps"/>
+
+    <!-- Fix translatable strings later. -->
+    <exclude name="Drupal.Semantics.FunctionT.WhiteSpace"/>
+  </rule>
+</ruleset>