Added a dotfiles setting to the repository settings. This complements the...

Added a dotfiles setting to the repository settings. This complements the --dotfiles command line argument used by add, addremove, extras, and changes commands. Useful in a project that always needs to process dotfiles so that the --dotfiles option does not need to be specified each and every time.

FossilOrigin-Name: b088c53fbde2b27a4f0ce86bc5296516aae29090