Revise the exclusive ordered comparison rules to no longer imply !=V.*

[dstufft]

Instead of having these operators imply a !=V.* this will instead have them more-or-less simply check if the prospective version is greater than or less than the specifier version. They will not however match a post or pre-release of the version mentioned in the specifier unless the specifier itself contains a post or a pre-release. In addition, we will ensure that >V does not match V+local.version even though it is technically greater than V.

In particular that means that something like >1.7 will match 1.7.1 but will not match 1.7.post1 while >1.7.post0 would. Likewise <3.0 would not match 3.0.dev0 while <3.0rc1 would.

This is implemented in pypa/packaging#25

[qwcode]

missing the closing ``

[ncoghlan]

Some minor editorial comments, and an actual error picked up by Marcus, but overall this looks good to me.

I unfortunately renamed the PEP 440 file based on the discussion in issue #2, so that will also need changing in the PR before it will apply cleanly again.

[dstufft]

This is updated now.

[ncoghlan]

Still another s/should/will/ here.

[ncoghlan]

Generally looks good to me - just one change that was missed from the previous review, and a realisation that the change log could likely use an introductory paragraph.

[dstufft]

Updated again.

[ncoghlan]

Merging this one - I'll also add the 'c'->'rc' normalisation change to the changelog, and then give folks on distutils-sig one last chance to comment before we publish the change on python.org

[dstufft]

At what point can I merge the packaging PR and release it?