IIRC this was the case with 0.8.6, so let's keep this to avoid the risk
of losing connectable nodes with 0.9 release.
Also our miniupnpc library was recently updated and I've heard
reports that it works better than before now.
- Add 'g++' package (virtualbox images don't have this by default)
- Workaround for determinism in Qt5 resources
- Pass --disable-maintainer-mode --disable-dependency-tracking to
configure for libqrencode to avoid random errors about missing m4
directory
- Fix typo -with-pic -> --with-pic
It is not necessary to rebuild dependencies after this commit.
Fixes#3610 and #3612.
