Update style configuration.

.clang-format

@@ -0,0 +1,51 @@
+---
+Language: Cpp
+BasedOnStyle: LLVM
+AccessModifierOffset: -4
+AlignConsecutiveAssignments: true
+AlignConsecutiveDeclarations: true
+AlignOperands: true
+AllowShortBlocksOnASingleLine: true
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterDefinitionReturnType: false
+AlwaysBreakTemplateDeclarations: Yes
+BraceWrapping: 
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: true
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: false
+  BeforeCatch: true
+  BeforeElse: true
+  BeforeLambdaBody: true
+  BeforeWhile: true
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBraces: Custom
+BreakConstructorInitializers: AfterColon
+ColumnLimit: 120
+IncludeCategories: 
+  - Regex: '^<.*'
+    Priority: 1
+  - Regex: '^".*'
+    Priority: 2
+  - Regex: '.*'
+    Priority: 3
+IncludeIsMainRegex: '([-_](test|unittest))?$'
+IndentCaseBlocks: true
+IndentWidth: 4
+InsertNewlineAtEOF: true
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: All
+SpaceAfterTemplateKeyword: false
+SpacesInAngles: false
+TabWidth: 4
+...