Application search - do not use generic names or comments

Searching for "the" shouldn't give me a list of applications. We should use the
keywords from applications' desktop files for search, not comments.

from canonical/unity-lens-applications/trunk/src/unity-package-search.cc
...
189 if (gmenu_tree_entry_get_comment (entry))
190 {
191 dum1 = unity_applications_lens_utils_preprocess_string (gmenu_tree_entry_get_comment (entry));
192 indexer->index_text (dum1, 0);
193 g_free (dum1);
194 }