Add options to instances for initial loading and contexts

[BertBeentjes]

Add options to instances to prevent loading instances with the page (used for search) and to use the default context, also an option for search.

/* add some flags to instances */;;;

ALTER TABLE positioninstances ADD COLUMN showonload tinyint(1) NOT NULL DEFAULT 0;;;

ALTER TABLE positioninstances ADD COLUMN usedefaultcontext tinyint(1) NOT NULL DEFAULT 0;;;