Most visible changes are:
* Database files locking. Only one process can write to them
in the same time.
* pkgdb -F is more smart now and takes OPTIONS, make.conf and
pkgtools.conf settings into account.
Moreover:
* Many bugs fixed.
* Many code refactored.
It's exactly like 2.1.3 but without summary messages and
fixed bug when BDB4 was defined but tried only bdb1 driver and
fall back to dbd driver.
- Add an option WITH_BDB1. Both BDB1 and BDB4 options can be off.
Ruby dbd driver will use in the case.