Minor pkg command changes

Made a few changes to pkg to address some things I came across while learning to use it recently.

pkg from-run and pkg from-pkg were supposed to require the -v version flag to append to the package name, but the wrong variable was checked
changed pkg from-docker to not append the version using a different format to from-run and from-pkg
Made pkg from-docker copy over the Program using the executable's actual name instead of just "program". Loading a package by default saves an image using the name of its executable. This resulted in the image being shown with the name “program” under ops image list, which as someone new to OPS was very confusing and led me astray regarding an unrelated problem I was having. It also means the images from different local packages overwrite each other. I didn’t know about the --imagename flag for ops pkg load at the time, but I think the default should be to use the original executable’s name as defined with e.g. the --file flag of ops pkg from-docker

Another change I wanted to make was to make ops pkg from-docker with the --copy flag copy over symlink files (the links themselves, not what they point to) into the package's sysroot. This was because the Python Docker image I was using tried and failed to use the version compatibility link libz.so.1 (among others) despite the linked to file, libz.so.1.2.11, being present in the sysroot, resulting in a crash. I figured it’d be in the spirit of “copying the whole file system” (as --copy is described) for something like a Python package to just work off the bat. I thought the change would be fairly trivial, but was mistaken; couldn't get it to work in a reasonable amount of time. Keen to hear thoughts on this

nanovms / ops

Minor pkg command changes #1544