Log message:
databases/libdbi-driver-*: rename Makefile_drivers to silence pkglint

Makefile fragments are commonly written in *.mk or Makefile.* files.
Using an underscore instead of a dot confuses pkglint.

Log message:
Update databases/libdbi-drivers-* to 0.9.0.

- some of the drivers now export client library functions to the
  programmer via the dbi_driver_specific_function() interface
- if necessary, the drivers now support libdbi instances
- a segfault in the oracle driver caused by INSERT statements was
  fixed
- the pgsql driver now supports features specific to PostgreSQL 9
  and later
- drivers now support transactions and savepoints if the
  underlying database engines do
- additional libdbi hint about position in a result set allows
  tremendous speedup of sequential reads from MySQL result sets
- various memory leaks were plugged
- database specific test scripts allow tests without affecting
  existing database clusters
- completely rewritten test kit increases coverage and improves
  error reporting

Log message:
Files related to libdbi DB drivers have been moved to
databases/libdbi-driver-sqlite3 directory. This fixes pkglint warnings
for databases/libdbi.

Log message:
Initial import of libdbi and its drivers for mysql, postgresql and sqlite
(2 versions); packaged for wip by Aleksey Cheusov.

libdbi implements a database-independent abstraction layer in C, similar to
the DBI/DBD layer in Perl. Writing one generic set of code, programmers can
leverage the power of multiple databases and multiple simultaneous database
connections by using this framework.