Bump pkgver/pkgrel of VCS packages. This should help with case (1) and
should not interfere with case (2).
(1) If the pkgver does not change after all then makepkg leaves the bumped
pkgrel untouched.
(2) If the pkgver does change then makepkg will reset the bumped pkgrel and
it is as if we haven't changed anything.
The old approach of using a local checkout does not work anymore
after the Git migration. One could use
`pkgctl repo clone --universe` to get a similar checkout but this
takes ages on my server. So let's better just download the
individual sources as needed, similar to how it is done for AUR
packages.
* Break backwards compatibility
* Allow to deserialize only base-data of packages and build
actions to potentially speed up showing tables
* Speed up package search in many cases by only deserializing
base-data (unless details are actually wanted)
