redone changes from pull request #19
fixed another issue which was previously fixed, but removed
added hook to override the value by which the report fields are grouped
fixed critical bug which allowed duplicate records to be displayed in report
Converted register() to store class references instead of instances, moved instantiaton to views
Merge pull request #21 from cristi23/master

redone previously overriden changes; fixed critical bug
add very basic test and travis
change travis file
rename travis
change travis env
change travis config and settings
fix env
fix refix fix
fix postgresql test problem
add travis build status image
removed unused imports
Disables cache class
Merge pull request #1 from ckinsey/master

Track reports by class, instantiate in views.
removed parameter from override_field_choices
fixed bug at groupby