Update pynn-brainscales to 2.0-rc5

* a few commits in pynn-brainscales (2), grenade (2), halco (2), hxcomm
  (2), haldls (1), hwdb (1)
  * add interface-draft for plasticity rules
  * support for requestion server-side information
    (`get_bitfile_info` and `get_repo_state`)
* also cleans up the tag mess in the dependent repositories…
  really same tag everywhere
* same for oppulance; as software state didn't change, we don't require
  oppulance to match pynn-brainscales version (rc2 is sufficient)…
  relaxing constraint, rc2