Version 4.7.4

• Fix call signature for pepxml.read and make it a full alias to pepxml.PepXML.
• Disable indexing of pepXML in pepxml.DataFrame, which fixes creation of dataframes from files with non-unique spectrum IDs.
• Allow iteration over search hits instead of spectrum queries with pyteomics.pepxml.PepXML.search_hits. pyteomics.pepxml.DataFrame has a new argument by, which accepts values "spectrum_query" (default) and "search_hit" (new).
• Fix #156.
• Fix #157 (#158 by @mobiusklein).