Move vector, project and network related core .cpp/.h files into
dedicated subdirectories.
An attempt to organise src/core better to make things easier to find.
Background: at project load time for all layers a copy of the style
is loaded and stored as a DOM document. This was implemented for
broken layers to make it possible to store the style back to the
project if a broken layer was kept in the project.
Of course this is not needed nor useful in a server context.
By introducing a new project load flag and using it in the server
config (projects) cache we allow to skip the initial storage of
styles for the server and cut the startup times of our test "monster"
project (~1000 PG layers) from 26 seconds to 15.
Before you ask: I chose to always store the original style
with the idea that we might have been able to use the original
style copy also to "restore" styles to their initial state.
This was never implemented, so I guess we might be good to
make the initial style copy selectively available for broken
layers only in order to speed up project loading in the general
case (desktop).
This commit adds a new avoid intersection mode setting when
digitizing new features. The three available modes are:
- allow intersections/overlaps
- avoid intersections/overlaps on active layer
- avoid intersectonss/overlaps on layers list
The third mode is what QGIS has had for a while, except
its UI/UX is a bit messy. The layers list is setup by
the user via the advanced snapping configuration widgets,
but isn't connected at all with whether snapping is
enabled / disabled.
This new approach makes it explicit to user whether
newly-added features might be clipped or not, and
if so by which layer(s).
Finally, the new 'avoid intersections/overlaps on
active layer' is likely a far more useful behavior
than having a list of layers (for e.g., you might
be digitizing on a layer that can't have overlap
with itself but is fine to overlap with another
layer, the latter also in need of avoid overlap
_with itself_).
