Add clang format

.clang-format

@@ -0,0 +1,59 @@
+---
+# ROOT Clang Format YAML configuration
+Language:        Cpp
+Standard: 		 Cpp11
+AccessModifierOffset: -2
+ConstructorInitializerIndentWidth: 4
+AlignAfterOpenBracket: true
+AlignEscapedNewlinesLeft: true
+AlignOperands: false
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortIfStatementsOnASingleLine: true
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: true
+AlwaysBreakTemplateDeclarations: true
+AlwaysBreakBeforeMultilineStrings: false
+BreakBeforeBinaryOperators: false
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BinPackParameters: true
+ColumnLimit:     120
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+DerivePointerBinding: false
+ExperimentalAutoDetectBinPacking: true
+IndentCaseLabels: false
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakString: 1000
+PenaltyBreakFirstLessLess: 120
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerBindsToType: true
+SpacesBeforeTrailingComments: 2
+Cpp11BracedListStyle: true
+Standard:        Cpp11
+IndentWidth:     2
+TabWidth:        2
+UseTab:          Never
+BreakBeforeBraces: Attach
+IndentFunctionDeclarationAfterType: false
+SpacesInAngles:  false
+SpaceInEmptyParentheses: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: true
+SpaceBeforeAssignmentOperators: true
+ContinuationIndentWidth: 4
+CommentPragmas:  '^ IWYU pragma:'
+SpaceBeforeParens: ControlStatements
+DerivePointerAlignment: false
+PointerAlignment: Left
+IndentWrappedFunctionNames: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+...