Make flexible the location of user configuration file with global options
Commit 41def7ca introduced the possibility to have a user config file executed after global_initialization.m. The location of this file is currently hard-coded.
The user should be able to choose the location of this file. The interface would be a new stanza/field in the already-existing ~/.dynare config file.
Other such "hook" files could be added at other places in the future.