added empty CalculateHistogram class, contribute to #5
added db support to CalculateHistogram class, contributing to #5
added testing code for histogram calculation
skip everything else than orders, skip status 8.xx orders
use more elaborate db query to simplify code
added OrderType to joined table
switched from manual day/article/order-counting to mysql-supported counting
report with finer granularity
added query.sql
minor fixes
streamlined query.sql
added sorting by ItemID
used another test interval (3 months)
replaced year, month, day grouping with intervall grouping
striped unnecessary information from query
added getIntervallQuery function
switched from manual to dynamic query generation
corrected range computation
adjusted starting timestamp
changed to k&r code style & indentation
added computation of adjusted daily sale
added getArticleAdjustedQuantity method
make use of new getArticleAdjustedQuantity method