Merge pull request #4 from IsabellaP/develop

Develop
prototype for web interface
dygraph 1.0.1
updated resampling routines and web interface
Updated resampling routines
Updated docstrings
bugfix
Merge branch 'develop' of https://github.com/TUW-GEO/poets into develop

Bug in local file
start_date set to 2000-01-01 by default
added option to resample png and tiff files