check code which generates id to remove spaces

[Becky Gibson]

The HTML spec says that id attributes should not have spaces. There are places in the dijit code where we generate ids to set up a labelledby relationship. As long as the item we are generating an id for does not already have an id OR it is an element that was generated by dijit, we need to replace any spaces with underscore. This was the cause of #8281. We were generating an id from the widget id. It happens that the widget id had a space in it and the labelledby relationship we were setting up did not work because Firefox 2 adheres to the spec and does not honor an id with spaces in it. We can't change the widget id since it may have been specified by a developer, but we should make certain that any generated ids do not include a space.

This likely to occur within the dijit code where we assigned aria labelledby or describedby attributes.

[bill]

FYI, for the 2.0 timeframe I'd like to disallow spaces in id's altogether. I filed #8289 to track that. But in the meantime this change makes sense.

[Chris Mitchell]

reassign due to inactive committer. please triage accordingly.

[bill]

Dup of #8489.