Format using google style

[costashatz]

Similar to https://github.com/ethz-adrl/ifopt/pull/90, this PR is applying the actual Google Style to all cpp files as mentioned in the CONTRIBUTING.md file.

For reference I used the following clang-format arguments:

{"Language": "Cpp", "BasedOnStyle": "Google", "AccessModifierOffset": -1, "AlignAfterOpenBracket": "Align", "AlignConsecutiveAssignments": true, "AlignOperands": "Align", "AllowAllArgumentsOnNextLine": true, "AllowAllConstructorInitializersOnNextLine": true, "AllowAllParametersOfDeclarationOnNextLine": false, "AllowShortBlocksOnASingleLine": "Empty", "AllowShortCaseLabelsOnASingleLine": false, "AllowShortFunctionsOnASingleLine": "Inline", "AllowShortIfStatementsOnASingleLine": "Never", "AllowShortLambdasOnASingleLine": "Inline", "AllowShortLoopsOnASingleLine": false, "AlwaysBreakAfterReturnType": "None", "AlwaysBreakTemplateDeclarations": "Yes", "BinPackArguments": true, "BreakBeforeBraces": "Custom", "BraceWrapping": {"AfterCaseLabel": false, "AfterClass": false, "AfterStruct": false, "AfterControlStatement": "Never", "AfterEnum": false, "AfterFunction": true, "AfterNamespace": false, "AfterUnion": false, "AfterExternBlock": false, "BeforeCatch": false, "BeforeElse": false, "BeforeLambdaBody": false, "IndentBraces": false, "SplitEmptyFunction": false, "SplitEmptyRecord": false, "SplitEmptyNamespace": false}, "BreakBeforeBinaryOperators": "None", "BreakBeforeTernaryOperators": true, "BreakConstructorInitializers": "BeforeColon", "BreakInheritanceList": "BeforeColon", "ColumnLimit": 80, "CompactNamespaces": false, "ContinuationIndentWidth": 4, "Cpp11BracedListStyle": true, "DerivePointerAlignment": false, "EmptyLineBeforeAccessModifier": "LogicalBlock", "FixNamespaceComments": true, "IncludeBlocks": "Preserve", "IndentCaseLabels": true, "IndentPPDirectives": "None", "IndentWidth": 2, "KeepEmptyLinesAtTheStartOfBlocks": true, "MaxEmptyLinesToKeep": 1, "NamespaceIndentation": "None", "ObjCSpaceAfterProperty": false, "ObjCSpaceBeforeProtocolList": true, "PointerAlignment": "Left", "ReflowComments": false, "SpaceAfterCStyleCast": false, "SpaceAfterLogicalNot": false, "SpaceAfterTemplateKeyword": true, "SpaceBeforeAssignmentOperators": true, "SpaceBeforeCpp11BracedList": false, "SpaceBeforeCtorInitializerColon": true, "SpaceBeforeInheritanceColon": true, "SpaceBeforeParens": "ControlStatements", "SpaceBeforeRangeBasedForLoopColon": true, "SpaceBeforeSquareBrackets": false, "SpaceInEmptyParentheses": false, "SpacesBeforeTrailingComments": 2, "SpacesInAngles": false, "SpacesInCStyleCastParentheses": false, "SpacesInContainerLiterals": false, "SpacesInParentheses": false, "SpacesInSquareBrackets": false, "Standard": "c++11", "TabWidth": 4, "UseTab": "Never"}

I copy-paste this into vscode's clang-format integration and get automatic formatting :)