To avoid excessive memory usage when opening in a directory with too many files.
Introduce the config variable config.max_project_files to choose the limit.
The mechanism introduced avoid using excessive memory but it fails to
let user access all the files in the directory. A better implementation
should not impose any limits but read each subdirectory on-demand, only
as they are expanded in the tree-view.
Francesco Abbate
16e6a6db9d