add projection support

For when views just don't cut it (i.e.: we need
a PK for merging)
fix WHERE condition on INSERT
forgot comma for bulk insert
Postgres UPDATE doesn't accept alias in SET

Also, separate initialization commands in waiting
for a better solution (automatically add ";" if it's
a file writer). Can't do it for now because I need to
find a general solution for newlining.
support choosing projection table engine
tune verbosity (be less annoying)