Avoid picking up tests in unpacked releases done for testing.

t/gitpan/repo/ is deliberately not cleared after each test so it's there
for debugging test failures.  If a test suite is stopped early this can
lead to "build test" picking up .t files in t/gitpan/repo/

Hard wire the recursive check for tests so it doesn't go too deep into
t/gitpan/repo/.  Make sure they come out in alphabetical order else
they will come out breadth first which is weird.
Dots are ok in Github repository names.

This is based on a number of actual Github repository distribution name translations.

For #104