Added `FCT_Record|Account_List_Table::get_views()` comments
Update `fct_count_posts` to query by meta key/value pair

The update now better reflects logic structure as from WP 3.9.
* Updated required import file format details
* Updated records list table count query conditions
* Fixed erroneous replacement of the term 'year' in `fct_time_since`
Parse `period_id` arg in `fct_count_posts` into proper period meta query args