Merge pull request #2 from elena/importer-rewrite

Adding necessary holding 'My First Account' to initial_data so csvimport is able to run.
Merge pull request #3 from elena/importer-rewrite

Tidying up moving model Admin classes to admin.py.
Default and action=append don't actually work together.
Make the help output formatting better.

(Big hack, need to refactor.)
Merge branch 'importer-rewrite' of github.com:mithro/timsfinance into importer-rewrite
Making the usage help even better.
Small document fixes (Fixes #8).
Refactor the test suite.

 * Check imported transaction amounts
 * Format the lists so diffs are better.
 * Spliting the different importer tests.
Adding DEBIT/CREDIT style CSV support.
Adding file header stuff.
Fixing the register for admin interface modules.

Fixes https://github.com/mithro/timsfinance/issues/11
Broken by 7a27f46389cd9b0b4b38f9a37026a69b18119109.