enchant: Minor fixes
enchant: Minor fixes

Remove superfluous cname_prefix namespace-attribute.
Add get_version() and fix array-length-type of Dict.suggest().

https://bugzilla.gnome.org/show_bug.cgi?id=767522

GNOME/vala,frida/vala,GNOME/vala,frida/vala,frida/vala,GNOME/vala,frida/vala,frida/vala,GNOME/vala