schemas/VegCore/VegCore.ERD.mwb: specimen_observation: added description (vegcore.vegpath.org?specimenDescription). taxon_presence: added occurrence_status (vegcore.vegpath.org?occurrenceStatus). stem_observation, aggregate_observation: made room for them to expand with additional first-class fields.

schemas/VegCore/VegCore.ERD.mwb: taxon_presence, taxon_absence: inherit from taxon_determination rather than taxon_observation, so that the taxon_determination's taxon can be used as the identifying taxon (i.e. the authorPlantName, VegCore.vegpath.org?authorPlantName)

schemas/VegCore/VegCore.ERD.mwb: taxon_determination: inherit from taxon_observation again because now that redeterminations can only occur on reobservable things, it makes sense to only allow one taxon_determination per observation event. this means that each redetermination on a specimen would get its own taxon_observation (where any additional attributes noted in the reobservation could also be included).

schemas/VegCore/VegCore.ERD.mwb: taxon_occurrence: renamed to reobservable to emphasize that this is only for things on which taxon redeterminations can be made, such as individuals and specimens (including voucher specimens). a redetermination on an aggregate_observation would instead be made on its voucher specimen, which is the only reobservable part of it.

schemas/VegCore/VegCore.ERD.mwb: moved taxon_observation subclasses closer to taxon_observation so that it would be clear they were observation-related rather than occurrence-related (e.g. there is no concept of "repeat-sampling" of an aggregate_observation, because each sampling it is the collector's opinion that the plants correspond to a particular taxon)

bugfix: schemas/VegCore/VegCore.ERD.png: switched back to attaching the sRGB color profile directly, because actually, the native->sRGB translation happens in the monitor driver itself (and can be adjusted in System Preferences > Displays > Color), rather than in the specific application. this means that the hex color values color-matched in MySQL Workbench were actually sRGB (translated by the OS to monitor-native for display), and that the sRGB profile merely needed to be explicitly indicated for other monitors that are not close to sRGB (and thus need the translation). the closeness of the 27-inch iMac screen to sRGB can be verified by selecting sRGB in System Preferences > Displays > Color, and noting that the desktop background does not change from when the default "iMac" setting is selected.

bugfix: schemas/VegCore/VegCore.ERD.png: convert to sRGB color profile after attaching the native monitor profile instead of attaching it directly. this allows the hex colors that were color-matched in MySQL Workbench (which presumably uses raw monitor RGB) to be translated to the universal sRGB space, where they can then be localized to a different monitor's local color space. note that this does not visibly change the image on the 27-inch iMac screen from what was produced via the previous, incorrect method (attaching the sRGB profile without conversion from native), which would imply that the iMac's screen is very close to the sRGB color space already. if this is the case, it is instead older LCDs that have off-white color spaces that need translation from sRGB.

schemas/VegCore/VegCore.ERD.png: attached sRGB color profile using Gimp (gimp.org), so that the colors don't look completely washed out and off-hue on older LCDs (i.e. other than the 27-inch iMac screen)

schemas/VegCore/VegCore.ERD.mwb: regenerated exports

schemas/VegCore/VegCore.ERD.mwb: added separate geo category (turquoise) to visually distinguish the broader geoplace tables from the more specific plot tables. (note that georeferencing is actually a plot table despite geo- in its name, because it assigns a geoplace to a plot.)