rhbz#915743: Avoid potentially blocking autocompletion for non file URLs
rhbz#915743: Avoid potentially blocking autocompletion for non file URLs

In theory, the logic of how SvtMatchContext_Impl threads are used to obtain
autocompletion information could probably be improved so that long-latency
scenarios would only block the ultimate closing of the dialog, if anything at
all.  In practice, this is probably not worth it, as users likely do not expect
an autocompletion feature for remote content, anyway.  (And previous commits
like 260afe56fd6b2f34de8290f3cdb7d1df5b88f8a8 "neon commands cannot be aborted"
make it questionable whether any remaining blocking upon closing of the dialog
could be bounded in a reasonable manner.)

Change-Id: Ie82b9a70285b30fe88cf4c40992710087e86815e

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core