Added viewer database interface concept
refs #542
Added some blank lines to db agent
refs #542
Fixed favourites table name
refs #542
Adding to favourites fixed
refs #542
Capitalized the name of local constant
refs #542
Reading photo metadata with gir originated module
refs #542
Import only metadata class form gexiv2
refs #542
Only one copy of photo in favs
refs #542
Func to check if photo already in favs
refs #542
Func for inserting many photos
refs #542
Fixed typo
refs #542
Func for executemany
Updated db manager
refs #542
Updated speller db agent
refs #542
If not exif use creation/modification time
refs #542
Corrected string values passing in db agent
refs #542
Only one record added to favs
Modified is in favs func
refs #542
Path and category as primary keys
Insert or ignore new records
Create tables if not exists in some funcs
refs #542
Path and category in favs
Select from favs with join expression
refs #542
Scanner results inserted to db
Items as tuples
refs #542
Fixed import in viewer model
refs #542