New: Dialog for 2 condition tests

New dialog for 2 conditions tests. This splits between and
within-subjects designs.
Minor cleanup

Changed some help text (removed redundant test code) and removed some
unnecessary code.
Cleaned up printing error

Old system, when printing out 2 ANOVA tables, somehow managed to put
the quotes together and the tables together. They are now presented as
quote then table properly.
Minor test changes

These test changes are fairly minor but made to work with 2-conditions
test dialog.
Bug in import SQLite dataset

There was a bug where a file saved and re-opened was expanded by 10
columns and rows each time. This removed that error so that what is
loaded is precisely what is saved.
Includes new 2 conditions test dialog

The new 2 conditions test dialog is now included.