The "trying to overwrite" error seems to be because you are going from the upstream packages to the native ones, and they're a bit different in which packages have some of the files.
So it's probably the apt-get purge command that fixed it (unless you tried that on its own before without luck?), since that would remove the conflicting files from the 14.04 package.
The "trying to overwrite" error seems to be because you are going from the upstream packages to the native ones, and they're a bit different in which packages have some of the files.
So it's probably the apt-get purge command that fixed it (unless you tried that on its own before without luck?), since that would remove the conflicting files from the 14.04 package.