lib/runscripts/in_datasrc_dir.run: datasrc_make(): use `if remaking ...` instead of accessing $_remake manually, for clarity

bugfix: lib/runscripts/in_datasrc_dir.run: datasrc_make(): use set_make_vars and $_remake as required in lib/sh/make.sh `remaking`

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/runscripts/table.run: added test_() target and use it in remake_VegBIEN_mappings() (it would not be clear that remake_VegBIEN_mappings() runs the tests)

bugfix: lib/runscripts/datasrc_dir.run: import(): don't run `sql/install` if the schema already exists, because this will try to rerun all the schema-creation queries. note that this idempotent functionality was not provided by the `make .../install` target that was previously used (idempotency is new with new-style import).

bugfix: lib/runscripts/datasrc_dir.run: import(): can't run `datasrc_make reinstall` anymore because this now defers to the runscript for new-style import datasources (which was done so that `make .../install` properly reinstalls all the datasources). instead, call the applicable make targets manually (there are just 2 of them).

lib/runscripts/table.run: table_make_install(): simplified the setting of $noclobber since there no longer needs to be a different command for when the log exists

bugfix: lib/runscripts/table.run: need to errexit the make target, so that errors in the SQL install scripts are not suppressed. this requires pre-checking if the table exists (using new pg_table_exists), so that the install target's errexit does not then need to be suppressed for cases when the table already exists.

bugfix: lib/runscripts/file.pg.sql.run: export_(): exclude Source and related tables so that these will be re-created by the staging tables installation instead, ensuring that they are always in sync with the Source/ subdir

bugfix: lib/runscripts/view.run: don't do anything in load_data(), to avoid trying to remake header.csv before the view is created. (for views, this instead happens in postprocess().)