Add clang-format typesetting hints

This approximates our current code style as well as possible.
For the actual code style guidelines, see github.com/Ultimaker/Meta.

Fixes Ultimaker#871.

clang-format

@@ -0,0 +1,35 @@
+---
+AllowAllParametersOfDeclarationOnNextLine: 'true'
+AllowShortBlocksOnASingleLine: 'true'
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: 'false'
+AllowShortLoopsOnASingleLine: 'false'
+AlwaysBreakTemplateDeclarations: 'true'
+BreakBeforeBinaryOperators: 'true'
+BreakBeforeBraces: Allman
+BreakConstructorInitializersBeforeComma: 'true'
+ConstructorInitializerAllOnOneLineOrOnePerLine: 'true'
+Cpp11BracedListStyle: 'false'
+DerivePointerAlignment: 'false'
+IndentCaseLabels: 'true'
+IndentWidth: '4'
+KeepEmptyLinesAtTheStartOfBlocks: 'false'
+Language: Cpp
+MaxEmptyLinesToKeep: '2'
+NamespaceIndentation: None
+ObjCSpaceAfterProperty: 'true'
+ObjCSpaceBeforeProtocolList: 'false'
+PointerAlignment: Left
+SpaceBeforeAssignmentOperators: 'true'
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: 'false'
+SpacesBeforeTrailingComments: '1'
+SpacesInAngles: 'false'
+SpacesInCStyleCastParentheses: 'false'
+SpacesInContainerLiterals: 'true'
+SpacesInParentheses: 'false'
+Standard: Cpp11
+TabWidth: '5'
+UseTab: Never
+
+...