Fix inconsistencies with how @description interacts with other tags

[jbrubake]

The presence or absence of @description has unexpected affects on how other tags are presented, including some being suppressed if @description is not present. This is likely due to how shdoc manages state for the various multi-line tags. The first step to a fix will be to identify the symptoms through testing. This will most likely lead to major refactoring of portions of shdoc. The investment is probably worth it because it would be an opportunity to better comment and document how shdoc works which would make it easier to add additional tags and features