1. constructed configuration files using override
It seems very complicated. How does it use?
2. name of configuration file
These names follow custom.
gtags.conf: resolv.conf, man.conf, ftpd.conf, ...
.globalrc: .bashrc, .vimrc, .elvisrc, ...
What kind of problem is there?
3. use configuration options instead of environment variables
Do you mean that we should use gtags_options (or global_options)
configuration variable instead of GTAGS_OPTIONS environment variable?
You are right. It corresponds to htags_options well.
4. ability to set and get configuration options, dump, ...
I don't know about 'git config'.
Would you explain it concrelely?