Dev deployment: extend db truncation

In case of pg client apps are missing (dropdb, createdb, etc), let's
connect to the default and proceed with truncation through DBI.
Dev deployment: fix cleanup logic

In case of passing "--kill", it should clean the env up anyway even if
rootdir is there, because rootdir might be missing while DB is still
there for some reason (as in case that script failed to drop db due
missing cmd utils - dropdb and createdb).
Dev deployment: update README
Add local-lib to gitignore