Qt 4 Builds

[Ben Cooksley]

Hi all,

As part of the CI overhaul, we've attempted to perform a complete set
of builds for Qt 4, as it's still (unfortunately) used.

Sadly, as expected for something nobody has really tried to build for
ages, many things don't build.
One of those is the entire PIM suite - because Baloo removed it's Qt 4
build metadata (meaning as far as the CI system is concerned, Baloo
has no Qt 4 branches and is Qt 5 only)

You've two options here:
1) Drop Qt 4 PIM.
2) Reinstate Baloo's Qt 4 branches.

I intend to carry out option #1 if there is no response to this.

As a general anecdote, the community needs to decide if we are going
to continue releasing and supporting Qt 4 builds at all. Considering
Qt 4 itself is EOL per upstream I believe, I think it's time we
followed suit.

Regards,
Ben