Makefile: fetch before checkout

Signed-off-by: Christopher Larson <kergoth@gmail.com>
gitignore: add cache

Signed-off-by: Christopher Larson <kergoth@gmail.com>
gitignore: improve sstate-cache ignore

Signed-off-by: Christopher Larson <kergoth@gmail.com>
Add fish setup script

Signed-off-by: Christopher Larson <kergoth@gmail.com>