sendmail: fix missing empty line between header and body

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: intro `user_exists` and `group_exists`

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/privileges: prevent seg faults with asserts and require in doc

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/curl: use more precise return types

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
Merge: Intro `user/group_exists` and apply a few small fixes

Pull-Request: #678
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>
tests: do not check whitespace errors in *.res files

Signed-off-by: Jean Privat <jean@pryen.org>
Merge: tests: do not check whitespace errors in *.res files

Pull-Request: #682
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>