Fix #8174 (overlaps when using 'avoid intersections' functionality) + test

I am not entirely confident if it will work perfectly with older versions of GEOS (< 3.3)
because of the lack of unary union (that is emulated by series of unions of two geometries)
Fix #9396 (deactivate datum transform dialog by default)

Added a checkbox in Options > CRS > Default datum transformations to re-enable the dialog when desired
[composer] Keep relative position of items when pasting (fix #8598)
[composer] Fix item selection after pasting items
Fix #8864 (Random selection with subsampling broken)
[QGIS-Server][WCS] Add RESPONSE_CRS param
Merge pull request #1145 from Cracert/i18n

[TRANSUP] pl: QgsOgr, context_help
remove label from standard option dialog template
Fix #9445 (crash during histogram diagram creation)
rearrange radiobuttons to avoid horizontal scrolling
[processing] fix docstring
debian packaging update (trusty)
Added an IT translator
Fix #6146 (Offline editing tool broken)

Adding of features back to remote database didn't work in case of primary keys
being auto-generated. With the fix, if the user did not set any value (i.e. it is NULL),
the value will be set to provider's default (and thus use the sequence generator)
Fix #8584 (WFS requests with FILTER fails against Geoserver)
IT translation
Fix compile error
update qgis.org links
also update links in translation files
debian packaging fix