When applying a solution, download all data before proceeding
Better action processing, error recovery and user report
Disable 'error recovery'

that worked really unreliably, and actually made the errors much more confusing.
Since we provide switch backups in case of error, the 'switch import' command provides
the same functionality in a user-controlled, clear and more reliable manner
Correct handling of sigint in sub-processes
Merge remote-tracking branch 'OCamlPro/fix-trains'

Conflicts:
	src/client/opamArg.ml