Bug 1025451: Include cartridge vendor in sdk cart ident function

Include the cartridge vendor when constructing a cartridge name/identifier from
the `primary_cartridge_name` function. This disambiguates cartridges provided by
other vendors (e.g. for builder cartridges such as Jenkins which will use the
identifier to construct new gears).
Merge pull request #4133 from ironcladlou/bz/1025451

Merged by openshift-bot