The build system now passes compiler directives based on the mode being build. By default data is stored in the source root (and this is encoded into the compiled binary). However, if building in user mode then data is assumed to be at the meson install prefix data directory
gcc versions 11 and before did not require this header to be manually specified, above that it does. As we move towrds a standardized compiler version I have brought opatIO in line with more modern gcc expectations
PreviouslyOPAT files were indexed using X and Z now they are indexed with a general index vector.
BREAKING CHANGE: all methods wch used X and Z now use std::vector<double> index (size: header.numIndex) instead. Also added a method to validate tables using checksum
opatIO can now read tables properly and retreive them in a useful manner. Future aditions will be the ability to lookup "closest" tables and a pretty printer for tables.
