Option for incremental wet deposition output

[pesei]

I'll plan to

1. Introduce a switch to reset deposition fields after output like in flexRISK versions
2. Implement & test option for using loutstep,loutaver,loutsample not only in concentration output but also in deposition output

Justification:

We use feature (1) in flexRISK and follow-up projects to reduce the size of the deposition output. I don't want to backfit this feature to any new FLEXPART version, and I think it's useful for everyone.

Feature (2) is a generalisation, and it will be useful for testing of wet deposition, possibly also other contexts.

We can decide whether it should be kept in mainstream Fp, but I thought I let everyone know about it, so they can make suggestions.

[pesei]

Replying to pesei:

1. Introduce a switch to reset deposition fields after output like in flexRISK versions

Implemented in r36 (see also diff:@33:36), as well as some other changes and corrections

Details in source:branches/petra/changelog.txt?rev=36​