0.2.b4

• Deprecated explicit setter interface to heparchy.write.hdf
• Implemented dictionary-style interface for user-named datasets within events
• Added iterator wrapper for writing events without explicitly using a context manager
• Added settings for compression, giving options between gzip and lzf
• Improved import system

Note: may introduce speed reductions for user-named datasets. Profiling and speed enhancements planned for future releases.