Merge pull request #694 from Mossop/bug817670

Fixes Bug 817670: Catch exceptions from NetUtil.asyncFetch. r=@ZER0(cherry picked from commit 73d8a8b0e8f9b4308ded44d48f35a5173740ddaf)
Merge pull request #680 from Mossop/bug819587

Fixes Bug 819587 - Clean up after some tests. r=@Gozala(cherry picked from commit 430c5a0027108e14c5c1221270855f9444aecaf1)