Re-factor "billing note"

Exchanging `patient_data.genericval2` for `patient_data.billing_note`
throughout the code base.  Also adding some Billing Report, 837, 835,
270, 271, and dated reminders fixes and tweaks.
Promoting discussion of removing the "generic" and "user" fields from
database.sql
Hi Art,

Need to keep your master branch clean or things will go to hell (I am exaggerating a bit, of course :) ).

Don't merge into your master like this. Then you won't know what you are testing on on all the branches based on this. To clean up, suggest on your local repo doing following:
# Go to master
git checkout master
# Reset your master to the commit prior to the merge commit
git reset --hard 24978cf2557ab527e83d7c58c6f1e48c6c8e842d
# Now overwrite your local branch master to your github repo (I am assuming you call it 'origin')
git push origin +master

And in future, when you want to feed your master from official codebase, follow these instructions:
http://www.open-emr.org/wiki/index.php/Git_for_dummies#Step_3:_Feeding_your_repository

-brady