Move gs parsing of generation and metageneration to handle_version_headers.
Merge pull request #1245 from jterrace/generation-after-update-fix

Move gs parsing of generation and metageneration to handle_version_headers
Fix regression in close_replace_key test created by #1245.
Merge pull request #1249 from jterrace/fix-clone-replace-key-test

Fix regression in close_replace_key test created by #1245.
Fix a bug in set_contents_from_file where it wasn't setting md5 properly.
Merge pull request #1250 from jterrace/fix-double-set-contents-bug

Fix a bug in set_contents_from_file where it wasn't setting md5 properly