bugfix: schemas/util.sql: join_strs_transform(): added back STRICT qualifier because it must be declared STRICT to use the special handling of STRICT aggregating functions

schemas/util.sql: %==(anyelement, anyelement): needs to be declared STABLE instead of IMMUTABLE because it depends on the search_path (as described at http://vegpath.org/links/#PostgreSQL:%20Documentation:%209.3:%20Function%20Volatility%20Categories%20**)

web/links/index.htm: updated to Firefox bookmarks: PostgreSQL: difference between STABLE and IMMUTABLE: functions that depend on the search_path: clarified that the confusing effects of using IMMUTABLE for one of these functions are only noticeable if the function is called on only constant values in a PL/pgSQL function (in which case the wrong search_path (the one in effect at create time) will be used)

schemas/util.sql, vegbien.sql: do not declare IMMUTABLE SQL-language functions as STRICT, because this prevents them from being inlined (as documented in the util schema comment)

web/links/index.htm: updated to Firefox bookmarks: PostgreSQL: added explanation of the difference between STABLE and IMMUTABLE, and common pitfalls in using IMMUTABLE when you should use STABLE. svn: added troubleshooting steps for running `svn upgrade` after the last Mac system update, which upgrades svn.

fix: schemas/util.sql: diff(text, text): use util.typeof() instead of pg_typeof() so the outputted query is runnable in any search_path

schemas/util.sql: added typeof(), which unlike pg_typeof() uses util.qual_name() to create a search_path-independent name

fix: schemas/util.sql: quote_typed(): schema-qualify the type so the expression does not depend on the search_path

schemas/util.sql: %== : use custom keys() function for the type, so that the user only has to get the keys from their value, not also write the comparison of those keys

schemas/vegbien.sql: synced from DB, which changes the order of the ~type tables