noise profile: panasonic gh-2 by thouks
noise profile: updated panasonic dmc-fz18 by sergey
Revert "Change the default behaviour of selection and hovering"

This reverts commit 139d24b4addc4c00df3162dff6923739b98bec1a.

+ some code comment.
noise profile: nikon d5200 by timur
[mi] : duplicate blend params too
masks : delete masks grp on iop reset
Button to select between to split view or overlay
Create snapshots table and add a snapshot number column to images table
Several snapshots history and name saving

 + Write snapshot's history to xmp (TO BE FIXED)
 + Write snapshot's history to db
 + Write snapshot's name to db
TODO: we also need to read snapshots info from xmp file
Small modification in colums name in snapshots table
Make sure the functions are defined before using them
Create snapshots table and update history one in existing db
Read all the snapshots information from the db and store it in the sidecar
Fix several compile errors
Read snapshots' history from XMP sidecar files
Write the snapshot history to the db when it is taken
Init the GUI with the snapshots stored in the db
Show in the UI the snapshots taken.