opkg: bump to version 0.3.0

opkg: bump to version 0.3.0

Remove "Disable tests and manpages" patch because opkg no longer
builds C tests into libopkg as of commit
ef8ae066cfa898b6366198e429cbeb4c94c92939.

Remove "Fix libtool issue with recent libtool" patch because the patch
comments indicate that it is no longer required with opkg version
0.3.0.

Select libarchive package dependency, as opkg requires it as of
release opkg-0.3.0-rc0 (see the opkg NEWS file).

[Thomas: add missing wchar dependency inherited from libarchive.]

Signed-off-by: Vanya Sergeev <vsergeev@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>