gtk interface building resulted in no gtk interface being built for some
reason, and reference working set ups all used qt, so this commit
switches interface to qt and fights with bugs that come from this
change.

QGtkStyle (needed for Proview-R) support in qt4 needs glib.
However, config script for qt4 is written in such a way that if glib is not
requested but QGtkStyle is requested, it just silently turns QGtkStyle off.

On the other hand, if glib is requested explicitly, then if script fails to
enable QGtkStyle it reports an error properly.
I think it was a bug in qt4 error reporting mechanism that made compilation go
smoothly even though requested QGtkStyle was never provided.
Nobody will fix it now though.

Anyway, this commit properly enables glib and fights with everything that rises
up as a result of this, leading to successfull QGtkStyle support.

https:// link just works more reliably as I found after several timeouts.

But I still have no idea why the second db folder spawns right inside
the frst one.

straighetend the configs:
no more custom source packages
using xvfb for proview compilation (easier)
fix bug with pwr pre-build process killing itself

Go1.15 is incremental improvement over Go1.14 with better compiler and runtime:

https://blog.golang.org/go1.15
https://golang.org/doc/go1.15

Don't drop support for Go1.13 yet, as that (no longer supported) Go
release is still being used by replication-manager and restic
components.

Remain default at Go1.14 yet.

Switch helloworld to Go1.15 and test this patch on that
software-release.

Going Go1.14.10 -> Go1.14.12 brings in runtime and security fixes:

https://golang.org/doc/devel/release.html#go1.14

Tested on helloworld SR.

See merge request nexedi/slapos!860

When invoking tests with setup.py test, missing eggs are installed before
running tests, using their latest available version, but we want to always
install eggs using buildout and using pinned versions.

The section template-slapuser-script creates the "bin/slapos" wrapper
which is needed inside runner-import.sh script.

Otherwise it's almost impossible to check for which node statistics are shown.

Fixes 8d5910dc

Limit stats to frontend entries only, as they are the most important for the
frontend operator, and also having thousands of entries makes the stats page
unusable.

fixes 8d5910dc

Despite the introspection has replaced old style Caddy-based log-access, some
bits were not removed, so remove then now.

fixes 0c830c4c