Add partial support of 'msvs_settings' section:

Supported sections are:

'VCLinkerTool' {
    'SubSystem',
    'AdditionalDependencies',
}
'VCCLCompilerTool' {
    'UsePrecompiledHeader',
    'WarningLevel',
    'WholeProgramOptimization',
}
Create 'msvs_precompiled_source' section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'Optimization': <value> } }
Create 'msvs_settings' { 'VCCLCompilerTool' { 'PreprocessorDefinitions': <value> } }
Parse 'Project/ItemDefinitionGroup/ClCompile/SDLCheck' section
Create 'msbuild_toolset' section
Create 'msvs_settings' { 'VCLinkerTool': { 'GenerateDebugInformation': <value> } }
Create 'msvs_configuration_attributes': { 'CharacterSet': <value> } section
Create 'msvs_settings' { 'VCLinkerTool': { 'LinkIncremental': <value> } } section
Create 'include_dirs' section
Fix bug: empty '/Project/ItemDefinitionGroup/Link/AdditionalDependencies' section in vcxproj ignored
Fix bug: '/Project/ItemDefinitionGroup/Link/GenerateDebugInformation' section ignored
Create 'msvs_settings' { 'VCCLCompilerTool' { 'DebugInformationFormat': <value> } } section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'RuntimeLibrary': <value> } } section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'FloatingPointModel': <value> } } section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'AdditionalOptions': <value> } } section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'ForcedIncludeFiles': <value> } } section
Create 'msvs_settings' { 'VCLinkerTool': { 'EnableCOMDATFolding': <value> } } section
Create 'msvs_settings' { 'VCLinkerTool': { 'OptimizeReferences': <value> } } section
Create 'msvs_settings' { 'VCCLCompilerTool' { 'SuppressStartupBanner': <value> } } section