Added handling for big datatables. Datatables with more than 100 rows are stored in the database in chunks of 100 rows to prevent OutOfMemory errors in PHP.
Replaced is_numeric() check by is_int() and is_float() because is_numeric rteturns true on strings containing numbers. Performance fixes in tests.
Merge pull request #7 from avorium/develop

Handling of big datatables and fix for numeric value handling implemented.