would be useful to be able to set texttest home from new application dialog

[Emily Bache]

When a complete newbie starts texttest for the first time, they may launch it from an innapropriate folder, and have neglected to set TEXTTEST_HOME. The new application dialog lets you choose a "subfolder" to store your tests in, but it won't let you choose a totally different folder. The newbie must know to either set texttest home before they start texttest, or know to start texttest in the same folder as where they will want to store their tests. It would be convenient to instead be able to select a folder for texttest home in the new application dialog. This would help newbies to understand how to use texttest.