fix: lib/runscripts/extract.run: export_(): explicitly prevent files from becoming web-accessible, to protect against an incorrect umask in the calling process

*{.sh,run}: runscript targets: use begin_target instead of echo_func so the target name is properly echoed. note that this requires using with_rm so that $rm is properly progagated to applicable invoked targets. (previously, $rm was progagated to all invoked targets. note that with_rm only works inside a runscript target that starts with begin_target.)

*{.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/runscripts/extract.run: added export_sample()

lib/runscripts/extract.run: use the extract-specific view instead of all of analytical_stem

added lib/runscripts/import_subset.run, extract.run