*{.sh,run}: use new begin_target instead of `echo_func; set_make_vars`

moved everything into /trunk/ to create the standard svn layout, for use with tools that require this (eg. git-svn). IMPORTANT: do NOT do an `svn up`. instead, re-use your working copy's existing files with `svn switch` (http://svnbook.red-bean.com/en/1.6/svn.ref.svn.c.switch.html).

lib/sh/db_make.sh: added pg_export_table_to_dir(), pg_export_tables_to_dir(). unlike db.sh pg_export_table_to_dir_no_header(), these functions are make-aware and will not clobber an existing file.

*{.sh,run}: use simpler .rel() instead of `. "$(dirname "${BASH_SOURCE<sup>0</sup>}")"/...` for relative includes

added lib/sh/db_make.sh that includes both db.sh and make.sh, and will eventually contain DB-related make commands