Core Version 1.7.1

+ Core - small change to getHomeHttp to try and fix IIS error.
+ Database
  o changed groupBy to group_by to match rest of variable names
  o Group by added on distinct columns only if count is not set.
  o getIndex can now be passed a table name. If it is not,
    assumes current table.
  o addColumn has a distinct parameter again.
  o Transaction support added.

+ DBPager
  o New method to determine total rows. If a primary index
    is found, counts on it.
  o New function setTotalColumn to force count column.
  o Pager clears order, columns, and group_by before figuring totals.

+ Database documentation updated with transation and addColumn
  information.
