is_authenticated and friends as properties

The documentation mistakenly referred to is_authenticated and friends as
properties, when in reality they were methods. However, they make good
sense as properties. This patch turns them into properties.
add Python versions
Merge pull request #182 from chhantyal/fix/trove_classifiers

add Python versions
Support for cookie paths
Allow login_user to set the session as not fresh
assertTrue(x in y) -> assertIn(x, y)
Use UTC methods for testing REMEMBER_COOKIE_DURATION
Merge pull request #191 from vesahautsalo/master

Support for cookie paths
Merge pull request #177 from lpsinger/anonymous_user_properties

is_authenticated and friends as properties
Fix session creation for every user

This fixes a wrong behavior in the strong protection. Now the
session protection is only tested if a session exists and
nothing is added to the session during the process.
Only one test is impacted and has been updated.