cli: refactor argument parsing

* cli: refactor argument parsing

- implementing -v, --version flag
- supporting GNU style long options with equal sign
  e.g. --eval="1 + 2"
- removing version from help output
- adjusting exit codes
- improving reporting of missing arguments & unknown options
- updating gitignore to include editor & os stuff

Author: vladimyr

.clang-format

@@ -1,49 +1,49 @@
----
+---
 AlignAfterOpenBracket: Align
-AlignConsecutiveMacros: 'true'
-AlignConsecutiveAssignments: 'false'
-AlignConsecutiveDeclarations: 'false'
+AlignConsecutiveMacros: true
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
 AlignEscapedNewlines: Right
-AlignOperands: 'true'
-AlignTrailingComments: 'true'
-AllowAllArgumentsOnNextLine: 'false'
-AllowAllParametersOfDeclarationOnNextLine: 'false'
-AllowShortBlocksOnASingleLine: 'false'
-AllowShortCaseLabelsOnASingleLine: 'false'
+AlignOperands: true
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
 AllowShortFunctionsOnASingleLine: None
 AllowShortIfStatementsOnASingleLine: Never
-AllowShortLoopsOnASingleLine: 'false'
+AllowShortLoopsOnASingleLine: false
 AlwaysBreakAfterDefinitionReturnType: None
 AlwaysBreakAfterReturnType: None
-BinPackArguments: 'false'
-BinPackParameters: 'false'
+BinPackArguments: false
+BinPackParameters: false
 BreakBeforeBraces: Attach
-BreakBeforeTernaryOperators: 'true'
-ColumnLimit: '120'
-ContinuationIndentWidth: '4'
-Cpp11BracedListStyle: 'false'
-DerivePointerAlignment: 'false'
+BreakBeforeTernaryOperators: true
+ColumnLimit: 120
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: false
+DerivePointerAlignment: false
 IncludeBlocks: Regroup
-IndentCaseLabels: 'true'
+IndentCaseLabels: true
 IndentPPDirectives: None
-IndentWidth: '4'
-IndentWrappedFunctionNames: 'false'
-KeepEmptyLinesAtTheStartOfBlocks: 'false'
+IndentWidth: 4
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: false
 Language: Cpp
-MaxEmptyLinesToKeep: '2'
-PenaltyReturnTypeOnItsOwnLine: '1000'
+MaxEmptyLinesToKeep: 2
+PenaltyReturnTypeOnItsOwnLine: 1000
 PointerAlignment: Right
-ReflowComments: 'true'
-SortIncludes: 'true'
-SpaceAfterCStyleCast: 'true'
-SpaceBeforeAssignmentOperators: 'true'
+ReflowComments: true
+SortIncludes: true
+SpaceAfterCStyleCast: true
+SpaceBeforeAssignmentOperators: true
 SpaceBeforeParens: ControlStatements
-SpaceInEmptyParentheses: 'false'
-SpacesBeforeTrailingComments: '2'
-SpacesInCStyleCastParentheses: 'false'
-SpacesInParentheses: 'false'
-SpacesInSquareBrackets: 'false'
-TabWidth: '4'
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+TabWidth: 4
 UseTab: Never
 
 ...

.gitignore

@@ -1,2 +1,7 @@
+.vscode
+.idea
+
 build/
 src/version.h
+
+.DS_Store