GH-32: convert dumbo.lib module to a package
GH-32: Add generic reducer to output raw files

- It is named RawReducer
- Handles outputing to single or multiples files (requires feathers)
- Include working examples to generate tokyo-cabinets, constant dbs, and jsonlines
- Last but not least, unittests!
create backend and fs as soon as possible (fixes GH-36)
Merge branch 'dangra-master'
make tests run on ubuntu with zope.interface installed (fixes GH-37)
version bump to 0.21.31
Added default paramater in Params class
Merge pull request #40 from andrix/master

'default' parameter in Params class
* added some parameters to tested map/red
don't divide system()'s return values by 256 (fixes #48)
Merge branch 'master' of github.com:klbostee/dumbo
version bump
use .wait() method of Popen object directly instead of reverting to os.waitpid()
Merge pull request #44 from brisssou/mapredtest_param

* added some parameters to tested map/red
point to (updated) homepage in README (fixes #34)
nicer URLs
Options refactoring across all the codebase, the change is backward compatible
a set of fixes after the refactoring, updated test too
Fixes on streaming, be consistent with old getopt function
more fixes related to refactoring