hgweb: fix diff hunks filtering by line range in webutil.diffs() The previous clause for filter out a diff hunk was too restrictive. We need to consider the following cases (assuming linerange=(lb, ub) and the @s2,l2 hunkrange): <-(s2)--------(s2+l2)-> <-(lb)---(ub)-> <-(lb)---(ub)-> <-(lb)---(ub)-> previously on the first and last situations were considered. In test-hgweb-filelog.t, add a couple of lines at the beginning of file "b" so that the line range we will follow does not start at the beginning of file. This covers the change in aforementioned diff hunk filter clause.