fix imports and namespaces in qplot

- Move tests from wrong directory
- Faulty identification of geom_bar "fixed" by removing the
  guess and in the test, after all geom_bar is the same as
  geom_histogram and the current difference will be fixed in
  an upcoming commit (PR #266)
Merge pull request #277 from has2k1/fix-qplot-imports

fix imports and namespaces in qplot
bump version
importing ggtitle
bump
forgot quotes
Minor pep8 fix.
Add binwidth to parameter list.
Merge pull request #282 from kalaidin/master

Adding binwidth to parameter list
Merge branch 'master' of github.com:yhat/ggplot
adding in percent label
bump
geom_abline fixed
Merge pull request #287 from EricChiang/master

geom_abline fixed
bump
WIP

Refactor ggplot, theme, and complete theme subclasses
* set default theme to theme_gray()
* use explicit api to callback to theme for applying rcParams and post_plot_callbacks
* remove __radd_ from theme subclasses
  this is pretty messy to get right better that it is only defined in the superclass due to the
  way python decides what to call when __add__, __radd__ are available for parent and child classes

Get the basic adding semantics of ggplot + theme and theme + theme
* Add element_text for themeing text
* themes can be combined iff compined in the correct order
  eg. axis_text + axis_text_x will work as expected but
      axis_text_x + axis_text will not.
* only theming text related to axis
* todo
  * more theme elements
  * more theme targets
  * proper combination of theme elements

More text theming added

TODO:
* complete rest of themes
* implement correct order of theme application regardless of theme construction
* fix python3 print error
* update images that were failing tests
rename module text to element_text
refactor element_text, move targets to the element and
create classes to handle configuration at the proper scope.
Fix python3 test fail
Sort element targets so themes are applied in proper order.