improved usage for pilerexport and pilerimport

improved pilerimport to support sphinx queries

logging option to the prepared statement

directory write ability check for some piler binaries

export emails based on from/to domain

initial commit using a very minimalistic db abstraction preparing to add postgresql support as well

preparing for database consolidation

improved pilerexport

added a tweak option to change the sent time piler stores

switching to prepared statements in attachment.c

introduced the server_id variable

fixed a bug (-A) in pilerexport

added tcp_wrappers support to the piler daemon

added tagging the search results

added retention rules to piler core

pilerexport fix

fixed the pilerexport utility

added pilerexport for bulk export to EML, and simplified pilerget