Initial implementation of CDF objects.
Added mandatory title, summary, unique tag.
Moved vesna/cdf.py -> vesna/cdf/__init__.py
Implemented saving results of a CDFExperiment.
Better pretty-print.
Use ISO datetime formats.
Add trace description.
Merge branch 'master' into cdf-support
WIP: cleaner implementation.
WIP: CDF rewrite.
Fixed error message
Operate with UNIX timestamps internally
Use logging module
Methodology is optional
Fixed typo
Composition instead of inheritance
Work with times relative to start, duration.
Save info about signal generators
Save data from experiment iterations.
Use ISO date format