Delete obsolete README.txt, symlink README with content

The old README.txt still links to a (wrong) SVN repo.
Document ``virtualpath:realpath`` syntax for mountpoints.

See .../Zope2/Startup/zopeschema.xml
Markup, mainly for literals
Move README to package root, move doctests to tests
Copy readable examples from doctests to README
The zope2-location option was removed.

In version 4.0a3 - 2010-01-24
Avoid "ValueError: need more than 1 value to unpack"

      File ".../collective.recipe.filestorage/plone.recipe.zope2instance-4.2.14-py2.7.egg/plone/recipe/zope2instance/make.py", line 16, in make_instance
        user, password = user.split(':', 1)
    ValueError: need more than 1 value to unpack
Instructions to retrieve test dependencies
Fixes to setup.py

README changed location.
Added 'manuel' to 'tests_require'.
@davisagli, updated your email address, OK?
Updated repo URL
Pin ExtensionClass version to allow buildout to complete
Merge branch 'master' of github.com:collective/collective.recipe.filestorage

Conflicts:
	buildout.cfg
Make the test buildout include the test extras

From https://github.com/collective/collective.recipe.filestorage/pull/3#issuecomment-39930844
Merge branch 'master' of github.com:collective/collective.recipe.filestorage

Move new doctests to `doctests.rst`

Conflicts:
	README.txt
	collective/recipe/filestorage/README.txt
Markup literal
Don't test against a version of Zope from 2009-10-11

I see that's why the `zope2-location` keys are in the tests.
It can't be right to test against a Zope much older than normally used
though.
Default to allow-implicit-cross-references false

Updates for newer packages: extending Plone 4.3 instead pulls in newer packages.
Mode changed

Thanks to mamico for spotting.
We don't care about the script mode?
Merge pull request #4 from jean/allow-implicit-cross-references

Disallow implicit cross references