Move some scripts from root directory to scripts/dev/

At the time of this commit, there is a dedicated folder for development
related tools and such scripts might fit better there to not bloat the
project root directory too much.

Move snapshot to scripts/dev/snapshot

diff --git a/snapshot b/scripts/dev/snapshot
similarity index 100%
rename from snapshot
rename to scripts/dev/snapshot

diff --git a/vcsclean b/scripts/dev/vcsclean
similarity index 100%
rename from vcsclean
rename to scripts/dev/vcsclean