Rename "error" to better support external references

[jugglinmike]

The spec includes a definition for the term "error." This is appropriate in the context of the document, but it is too generic for use in other specifications--notably, those that define WebDriver extension commands.

This issue came up in a proposal to define an extension command in the Permissions specification. There, @jyasskin commented:

I'm uncomfortable with WebDriver reserving the term "error" globally.

To be clear: this issue does not interfere with the use case of extension commands. External specifications may reference this document's "error" however they wish. (This is what @jyasskin suggests for the Permissions specification.)

However, that seems like it may become a common enough concern to warrant a change here. As @ato suggested:

Would renaming WebDriver’s error definition to, say, WebDriver error or
something better make WebDriver a better citizen for other specifications to
hook into?

This issue is intended to facilitate discussion about that change. Would the editors be open to a patch which re-named "error" to "WebDriver error"?

[andreastt]

I’m in favour.

[jyasskin]

I also have no objections to the webdriver spec using "error" locally to refer to this concept. In Bikeshed, you'd represent this with https://tabatkins.github.io/bikeshed/#local-lt, but I don't actually see a way to do it in respec.

[andreastt]

It would be <dfn data-lt=error>WebDriver error</dfn> in ReSpec.

[jyasskin]

I think data-lt in ReSpec is the same as lt in Bikeshed, and that sets a global name, not just a local one.