Adding parameterized documentation tests to scoremanager branch.

Added two new functions to mainline documentationtools:

    * documentationtools.list_all_scoremanager_classes()
    * documentationtools.list_all_scoremanager_functions()

Alas, the functions do not work yet.

Calling them produces an ImportError in ModuleCrawler:

    Traceback (most recent call last):
    File "/Users/trevorbaca/.abjad/abjad_tmp.py", line 19, in <module>
        print documentationtools.list_all_scoremanager_classes()
    File "/Users/trevorbaca/Documents/abjad/abjad/tools/documentationtools/list_all_scoremanager_classes.py", line 32, in list_all_scoremanager_classes
        for x in class_documenter():
    File "/Users/trevorbaca/Documents/abjad/abjad/tools/documentationtools/ClassCrawler.py", line 46, in __call__
        for module in self.module_crawler:
    File "/Users/trevorbaca/Documents/abjad/abjad/tools/documentationtools/ModuleCrawler.py", line 103, in __iter__
        module = __import__(module_name, fromlist=['*'])
    ImportError: No module named scoremanager.core.ScoreManager

Will open in GitHub.