Refactor some of the configuration file handling code. Make it easier to get the actual file that was processed, and allow extras in the config file to be ignored (default now), captured or errored.
fix std::error reference and formatting
add test for required but no default and fix a shadow warning on 'required' from gcc 4.8
Test correctness of config write-read loop
fix config generation for flag definitions
make the config output conform with toml
continue work on the config file interpretation and construction
get all the ini tests working again with the cleaned up features.
update formatting
rename IniTest to ConfigFileTest to better reflect actual tests and add a few more test of the configTOML
disambiguate enable/disable by default to an enumeration, and to make room for a configurable option to allow subcommands to be triggered by a config file.
add a ConfigBase class to generally reflect a broader class of configuration files formats of similar nature to INI files
add configurable to app and allow it to trigger subcommands
add test of ini formatting
add section support to the config files so sections can be opened and closed and the callbacks triggered as appropriate.
add handling of option groups to the config file output
add subcommand and option group configuration to config file output
subsubcom test on config files
fix a few sign comparison warnings and formatting
start working on the book edits for configuration and a few more tests
more test to check for subcommand close in config files
more tests for coverage
generalize section opening and closing
add more tests and some fixes for different configurations
yet more tests of different situations related to configuration files
test more paths for configuration file sections
remove some unused code and fix some codacy warnings
update readme with updates from configuration files
more book edits and README formatting
remove extra space
Apply suggestions from code review
Co-Authored-By: Henry Schreiner <HenrySchreinerIII@gmail.com>
fix some comments and documentation
fix spacing
Rename size_t -> std::size_t
Fix compiler warnings with -Wsign-conversion
Fix new warnings with -Wsign-conversion in PR
