Merge branch 'jc/maint-abbrev-option-cli' into maint-1.7.11

We did not document that many commands take unique prefix abbreviations of long options (e.g. "--option" may be the only flag that the command accepts that begin with "--opt", in which case you can give "--opt") anywhere easy to find for new people. * jc/maint-abbrev-option-cli: gitcli: describe abbreviation of long options