Fetch: Support --gitignore option
Fetch: Support --gitignore option

Being a command that actually employs (optional) .gitignore file
usage to ignore files on downloading from "TFS", let's make `--gitignore`
option accessible here, too, for both consistence and user convenience.

This allows using `--gitignore` with file path value to temporary
enable "git-tfs" .gitignore file support for `fetch` command duration,
using external .gitignore file where one may not be part of "Git"
repository already (like when otherwise `--gitignore` option is used
with `clone` command, but _both_ committing provided .gitignore file
to "Git" repository _and_ using it to ignore files).

Signed-off-by: Igor Djordjevic <223f16a1994a362e136d5c878453efc894c68d90@gmail.com>

pmiossec/git-tfs,PKRoma/git-tfs,git-tfs/git-tfs