Use fbsource clang-format config

Summary:
This mirrors the clang-format config used by fbsource to Yoga.

They are pretty similar, except for an annoying habit where Yoga's previous forced small functions in headers to be a a single line, so you would get a combination of multiline and single line functions next to each other which are hard to read. That is what motivated this change.

It also enforces header ordering (yay). I don't think we have any side-effect causing headers, so this should be safe.

Reviewed By: yungsters

Differential Revision: D49248994

fbshipit-source-id: 66998395e7c0158ff9d9fb1bee44e8401bdd8f21

.clang-format

@@ -1,61 +1,3 @@
-Language: Cpp
-AccessModifierOffset: -2
-AlignAfterOpenBracket: AlwaysBreak
-AlignConsecutiveAssignments: false
-AlignConsecutiveDeclarations: false
-AlignEscapedNewlines: Left
-AlignOperands: false
-AlignTrailingComments: false
-AllowAllParametersOfDeclarationOnNextLine: false
-AllowShortBlocksOnASingleLine: false
-AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: Inline
-AllowShortIfStatementsOnASingleLine: false
-AllowShortLoopsOnASingleLine: true
-AlwaysBreakAfterReturnType: None
-AlwaysBreakBeforeMultilineStrings: true
-AlwaysBreakTemplateDeclarations: Yes
-BinPackArguments: false
-BinPackParameters: false
-BreakBeforeBinaryOperators: false
-BreakBeforeBraces: Attach
-BreakBeforeTernaryOperators: true
-BreakConstructorInitializers: BeforeColon
-BreakInheritanceList: BeforeColon
-BreakStringLiterals: true
-ColumnLimit: 80
-CompactNamespaces: false
-ConstructorInitializerAllOnOneLineOrOnePerLine: true
-ConstructorInitializerIndentWidth: 4
-ContinuationIndentWidth: 4
-Cpp11BracedListStyle: true
-DerivePointerAlignment: false
-FixNamespaceComments: true
-IndentCaseLabels: true
-IndentPPDirectives: None
-IndentWidth: 2
-IndentWrappedFunctionNames: false
-MaxEmptyLinesToKeep: 1
-NamespaceIndentation: None
-PenaltyReturnTypeOnItsOwnLine: 2000
-PointerAlignment: Left
-ReflowComments: true
-SortIncludes: false
-SortUsingDeclarations: true
-SpaceAfterCStyleCast: true
-SpaceAfterTemplateKeyword: true
-SpaceBeforeAssignmentOperators: true
-SpaceBeforeCpp11BracedList: false
-SpaceBeforeCtorInitializerColon: true
-SpaceBeforeInheritanceColon: true
-SpaceBeforeParens: ControlStatements
-SpaceBeforeRangeBasedForLoopColon: true
-SpaceInEmptyParentheses: false
-SpacesBeforeTrailingComments: 1
-Standard: Cpp11
-UseTab: Never
----
-Language: ObjC
 AccessModifierOffset: -1
 AlignAfterOpenBracket: AlwaysBreak
 AlignConsecutiveMacros: false
@@ -165,4 +107,3 @@ Standard: Latest
 TabWidth: 8
 UseCRLF: false
 UseTab: Never
-...