GPasteItem: add method to get size

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteUrisItem: override get_size

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteImageItem: override get_size

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GpasteHistory: track biggest item + size

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteHistory: don't track active item as biggest

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteHistory: elect biggest when loading

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteImageItem: size is different when inactive

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteHistory: always reelect when biggest goes off

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
add new setting for max memory usage

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
settings: bump sonames

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Merge branch '3.0'

* 3.0:
  settings: bump sonames
  add new setting for max memory usage
  GPasteHistory: always reelect when biggest goes off
  GPasteImageItem: size is different when inactive
  GPasteHistory: elect biggest when loading
  GPasteHistory: don't track active item as biggest
  GpasteHistory: track biggest item + size
  GPasteImageItem: override get_size
  GPasteUrisItem: override get_size
  GPasteItem: add method to get size