* introduce class LinkFilter to handle link filter operation (and lighten LinkDB).
* handle 'private only' in filtering.
* update template to prefill search fields with current search terms.
* coding style.
* unit test (mostly move from LinkDB to LinkFilter).
PS: preparation for #358#315 and 'AND' search.
Modifications
- rename `pageCache` to `CachedPage`
- move utilities to `Cache`
- do not access globals
- apply coding rules
- update LinkDB and test code
- add test coverage
Signed-off-by: VirtualTam <virtualtam@flibidi.net>
Relates to #218
Removes "hidden" access to the following variables:
- $GLOBALS['config']['datastore']
- PHPPREFIX
- PHPSUFFIX
Signed-off-by: VirtualTam <virtualtam@flibidi.net>
