bugfix: lib/sh/util.sh: log+: PS4 when $1 < 0: need to negate $1 because now it's a negative number

lib/sh/util.sh: log--: use log+ with 1 instead of log so we don't need a separate log- function

lib/sh/util.sh: logging: log+: support negative log_level adjustments. log-: use log+ with the negative of its argument

web/links/index.htm: updated to Firefox bookmarks. sorted MySQL and PostgreSQL sections.

web/links/index.htm: updated to Firefox bookmarks

web/links/index.htm: Mac 10.8 Mountain Lion > PostgreSQL: appended tab to name to disambiguate it from the general PostgreSQL section

bugfix: web/links/index.htm.run: prepend __ to the HTML anchors of bookmarks toolbar links so they don't shadow/override folders of the same name: also renamed the corresponding self-anchor hyperlinks

bugfix: web/links/index.htm.run: prepend __ to the HTML anchors of bookmarks toolbar links so they don't shadow/override folders of the same name: need to replace all occurrences (using /g option to sed) to include both HTML anchors on the line

web/links/index.htm.run: prepend __ to the HTML anchors of bookmarks toolbar links so they don't shadow/override folders of the same name

lib/sh/util.sh: sed: changed it to an alias so it will also be expanded when passed to an external command (like in_place) that can only run an executable, not a shell function (this occurs as long as the external command is defined as an alias which ends in space, to alias-expand the next word). added associated $sed_cmd var for cases when there is no alias wrapper around the external command, and the literal alias body must be used instead.