Add configuration support for setting the fetch timeout

This adds the configuration variable "FETCH_TIMEOUT", which
sets the timeout used by the fetch library to something the
user wants, retaining the old value of 30 as a default.
Put FETCH_TIMEOUT at the end.

Perhaps I should have put them at the end, because of when they
were added rather than trying to be clever and grouping them
with similar items.
Merge pull request #460 from dannomac/master

Add fetch timeout, same as on release-1.0 branch.