<rdar://problem/13270271>

Only add the — (double dash) separator to a command syntax if it has any options to be separated from arguments
Also remove the unused Translate() method from CommandObject 

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@184163 91177308-0d34-0410-b5e6-96231b3b80d8