v0.9-beta

This is a significant jump in the release. Many modifications have been made and will be added to the documentation in the coming days. Among the many changes:

• New indices have been added with documentation and call examples
• Run_length based operations have been optimized
• Support for CF non-standard calendars
• Automated/improved unit conversion and management via pint library
• Added ensemble utilities for creation and analysis of muti-model climate ensembles
• Added subsetting utilities for spatio-temporal subsets of xarray data objects
• Added streamflow indicators
• Refactoring of the code : separation of indices.py into a directory with sub-files (simple, threshold and multivariate); ensembles and subset utilities separated into distinct modules (pulled from utils.py)
• Indicators are now split into packages named by realms. import xclim.atmos to load indicators related to atmospheric variables.