Implement (meta-)data collector API
Create subpackages for collector implementations
Implement sum collector
Workaround for spurious columns in input data sets
Bug fixes
Implement __str__() on collector collections
Code for basic working example
Add TODO
Base implementation for collector result distance
letter count collector
Bug fix

  - ItemCollectorSet.__str__() needs to supply a reference to itself when callling ItemCollector.get_result()
Merge branch 'master' of bitbucket.org:malteworld/infint-2014
Merge branch 'master' of bitbucket.org:malteworld/infint-2014
letter average collector
added letter average to output
division by floating point
Minor changes
Multiphase collectors (1/3)

- Collectors can access the collectors of the preceding phase
  during their construction
Multiphase collectors (2/3)

- Adapt existing collector constructors to take the additional
  argument for the preceding phase
Multiphase collectors (3/3)

- Implement a basic manager for multiphase collectors