Fully migrated checkapicommon into model_src/include/ to remove need to 'deploy' by copying
Added basic python/c errno, stopped verify_c.py from translating impl/model fd's upon failure but with errno=0
Added apr_file_close, fs debugging
Separate model and impl fd translation logic into a class
Rearrange fd translation, better arg output with debugfs
In emulated fs: started flag support and dup2. Started apr_file_dup[2] modeling