Extension for selection and storage of profile points

[cxcandid]

This PR contains a small extension for the selection and storage of profile points in a “profile_points” layer.

[nicogodet]

Could you make the feature deactivable and disable by default ?

User could also choose an existing layer instead of a new memory layer. What do you think ?

Nevertheless good feature!

[cxcandid]

@nicogodet do we really need to make this feature deactivable? ...there is no other function that would be in conflict here.

[nicogodet]

@nicogodet do we really need to make this feature deactivable? ...there is no other function that would be in conflict here.

People can miss click on Canvas and create an unwanted layer.

[cxcandid]

Added a checkbox for activating/deactivating point storage.

[nicogodet]

Could you rebase and update plugin version ?

Could you provide user a feedback that point has been added to profile_points layer using self.iface.mainWindow().statusBar().showMessage("your_message") ?

The "Options" group box is getting more and more crowded and I don't like that, it reduces the layer tree above. I might move most of checkboxes to Settings tab in full resolution groupbox (and rename this groupbox). If you are motivated, you can do this moves. Otherwise I will do it but it might delayed the release of new version...