Add "updateinfo" command. (RhBug:850912)

Please note that https://github.com/akozumpl/hawkey/pull/64 is required for proper non-ASCII chars handling. And at least the version bump is needed to prevent nightly builds failures.

For the record:
- ```updateinfo info``` does not display information that is not accessible through libsolv.
- advisories may be sorted differently -- it was easier to implement
- the output formatting may be slightly different (I would say better/fixed) -- it was easier to implement
- output of any sub-commands is affected by ``--exclude`` (in YUM, it affects only ```updateinfo updates```) -- it was easier to implement
- ```enhancement``` and friends are recognized at any ```<spec>...``` position (not only at the first position like in YUM) -- it allows to filter by multiple advisory types at once
- advisory IDs and package names are also matched against ```enhancement``` and friends -- I think it makes the command more consistent
- advisory reference IDs are not matched

None of these properties are described in YUM man pages.

```updateinfo [bugzillas|cves]``` are not supported yet, because they only affect ```updateinfo list``` and they make the output very different -- I think it would be better to add a new sub-command for it.
```updateinfo [severity|recommended|new-packages]``` are not supported yet, because the are not supported on the Hawkey level.

However, I'm going to close the bug after merging these changes, because I believe that this is enough to close it.
No, I don't mean parsing the output: I suggest the table generation is extracted into one function and that is tested for its output (i.e. similar to the tests above). Then extract the functionality that supplies the data into another function, it will probably return a bunch of advisories or packages or what have you. Then write a test that tests against these return values. The whole goal is not to test the table generation many times but just the necessary amount. Does it make sense?