aurman: aurman does not support `--` to mark the end of options

Description

-- is not recognized, and cannot be used to mark the end of options (to ensure following arguments are not handled as options even if they start with -).

Expected Behavior

> pacman --sync --search -- -viewer
extra/gnome-font-viewer 3.28.0-1 (gnome)
    A font viewer utility for GNOME
community/deepin-image-viewer 1.2.22-1 (deepin)
    Deepin Image Viewer
community/deepin-shortcut-viewer 1.3.5-1 (deepin)
    Deepin Shortcut Viewer
community/gpx-viewer 0.4.0-1
    Simple tool to visualize tracks and waypoints stored in a gpx file
community/ristretto 0.8.2-2 (xfce4-goodies)
    Fast and lightweight picture-viewer for Xfce4
community/virt-viewer 6.0-1
    A lightweight interface for interacting with the graphical display of virtualized guest OS.
community/youtube-viewer 1:3.3.4-1 [installed]
    Command line utility for viewing YouTube videos

Current Behavior

> aurman --sync --search -- -viewer
2018-05-31 13:04:41,108 - parse_args - parse_pacman_args - ERROR -  is too short
:: aurman --help or aurman -h

Steps to Reproduce

See example above.