Apport add_info hook should not add ppa version as tag

Users trying to report a bug on unity when it comes from a ppa such as ppa:sil2100/quantal (currently at version 6.0.0-0ubuntu5~test1) get an ugly error from apport, then if they try the fallback method get an ugly error from launchpad. See for instance bug 1024836 comment 3, which also involves further apport fallout on quantal.

This is because launchpad enforces tags are in a particular form:

    "Tags must start with a letter or number and be lowercase. The characters "+", "-" and "." are also allowed after the first character."

However, debian policy also allows ":" and "~" in package versions:

    <http://www.debian.org/doc/debian-policy/ch-controlfields#s-f-Version>

The unity apport hook should either not add the version as a tag (it appears prominently in the Package field anyway, along with a reference to ppa origin), or should ensure the tag is in fact valid.