NEXUS-6139: Modified delete operation

Now the items will be deleted permanently,
not sent into trash.
NEXUS-6138: Removed complex option passing

And be explicit, as aside of REPLACE no other
option were used in consistent way.
Merge pull request #262 from sonatype/NEXUS-6139-evict-delete-operation

NEXUS-6139, NEXUS-6138: Evict delete operation and copy options