Let AssertionErrors bubble up

Sometimes we want to use AssertionError to cause test
failures, and it is unlikely to be used in real code,
so just let the error bubble up if it is encountered
while loading a plugin.

Change-Id: I7ad20b0796c1a02427d324aa7f35bb238013c425
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
fix typo in docstring

Change-Id: Ide52b81d292e16ab086acf7d5f93b579bf233b1d
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
Check the names of plugins before importing them

Update NamedExtensionManager to check the names of the plugins
before loading any code to avoid importing anything we are not going
to use.

Fixes issue #4

Change-Id: I27b19cb42ca3d165ce45953281b82e394c4539a2
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
update settings for 0.8 release

Change-Id: I15c465d1c4883d6db08638bbe5ed1f83a82477b5
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>