fixed test/default_toolset.py

[paolopas]

• removed test_default_toolset_requirements^[1]
• removed test_conditions_on_default_toolset^[2]
• added test_default_toolset for testing of build-system.set-default-toolset rule
• optimized default-toolset selection in build-system.jam

Note

Do we really need test/results-python.txt?

^[1]

test_default_toolset_requirements has the following problems:

• Improperly uses feature.get-values, since it is not intended to process conditionals, and even if it were, it would not be correct to write one like the ones used in the test, i.e.: <description>toolset-requirement:<description>conditioned-requirement considering that "Free features can never be used in conditionals" as I found written in a comment in build/feature.jam (who knows if it's true... the test could have also avoided creating the description feature and used the default define.)
• The buildRule used in the notfile testTarget target cannot see the properties set on the toolset with the toolset.add-requirements because the Jamfile is loaded before the using of the default toolset is executed, i.e., before the toolset.add-requirements is called.

^[2]

The test_conditions_on_default_toolset is affected by the same issues as the test_default_toolset_requirements above.