Adding missing test and docs
Merge pull request #204 from hyrise/feature/groupby_doc_test_fix

Adding tests and docs
adds function for parameterized loading of (json) files
allows SortScan to order by column name (and still by column number)
adds function for parameterized loading of (json) files
allows SortScan to order by column name (and still by column number)
executeAndWait now support setting trasactionID
new tpcc test tables, and almost complete Delivery Test
[wip] more trasaction tests implemented
fixes issues with tpcc tables and queries
fixes a problem in autojson query (...?)
json queries can now use between expression
4 Transactions (almost) complete, Payment still missing

* and parameterized loading can now output ints with a set length
  (e.g. 02 istead of just 2)