Moved import-related code to new file
Renamed test files
Refactoring the import machinery.

Broke up importer functions into three - 'finder' functions, 'loader' functions and 'importer'
functions. Finders get the list of modules in a folder; loaders import the modules,
and importers co-ordinate the process.
Added MethodFinder.

Functions that find special methods are no longer free functions; they are bound
to the MethodFinder class.
renamed some test methods
refactored the way it finds modules
no longer importing non-test modules from a test package