SvxBackgroundColorItem inherits from SvxColorItem and for backwards
compatibility with the StarOffice 5 binary file format (yes, really)
writes/reads only rgb and not the transparency value, so copying and pasting
text from a sidebar comment in writer to itself or another one results in a
black character background as the default COL_AUTO turns into black

Change-Id: I18b5105dd8e060b9e49dda6026e26d3a0f00d8f5
(cherry picked from commit 3bc69b1d)

this farcical staroffice 5.0 related junk can at least be const

Change-Id: I096d98f6e0cb61cacd9cd82a623f832b88ded1e6
(cherry picked from commit 1e8b7cdb)
Reviewed-on: https://gerrit.libreoffice.org/18087Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>