changing applicability api to not preload units
adding search_all_unit_ids to SearchUnitsMixin to search for units with criteria without translating them to plugin units
minor fix on search units mixin
assigning NoneType criteria to an empty dictionary to be able to convert it to the Criteria object
removing unwanted additional step
renaming parameters passed to find_applicable_units api
Moving search_units call to profiler conduit and unit_criteria parsing to webservices layer instead of applicability manager
Removing redundant if
updating profiler conduit call to return unit ids instead of units
Merge pull request #486 from pulp/skarmark-applicability

changing applicability api to not preload units in the platform