Move document classes and tests from products to portal_components.

In order to have git recognized this as a move, I used that procedure:

for each document, for example with Budget.py:

• in portal_components, add a new Document Component with id document.erp5.Budget and reference Budget. Leave text content empty for now.
• in portal_templates, from Document Classes tab of erp5_budget business template, add document.erp5.Budget
• click on the Git tab, this will populate the working copy.
• from the command line, use git mv to move Budget.py from products to bt, something like:

   git rm bt5/erp5_budget/DocumentTemplateItem/portal_components/document.erp5.Budget.py # remove the empty "placeholder" file
   git mv product/ERP5/Budget.py  bt5/erp5_budget/DocumentTemplateItem/portal_components/document.erp5.Budget.py # actual move

• ( at this point it is easier to make a commit that we'll squash together later)
• Fix import paths, for example Products.ERP5.Document.Budget becomes erp5.component.document.Budget

for tests:

• find out the test dependancies. In this case, it was all business templates defined in getBusinessTemplateList method of the test class and erp5_full_text_myisam_catalog that is a virtual dependancy and that we always have to specify.
• list the test dependencies in Tests Dependencies from the business template View tab.
• move the test using same git mv trick. This time adding a Test Component named test.erp5.testBudget.

Running test as live test does not seem to work when running from the instance, but the test passes when running on test nodes ( test results are OK, the 2 failures are same on master)

I did just a little development on the migrated products, so there might be severe usability problems, but as far as I saw it seems working for me. Also, for the records, note that I have locally disabled pylint and use a hack to just use pyflakes.

At the same time, I am pushing a trivial commit 488f557c of a simple mistakes that integrated python code checker revealed.