Show linenumbers next to errors

[TrueBrain]

Currently errors are shown in the order they are found. But it can be difficult to figure out where it comes from, in which template, etc.

Adding linenumbers (and Pages / Templates that generated the error) can really help here.

But this is far from trivial: a template can be included multiple times, so you should shown some list of include-tree where the problem happened. Additionally, wikitextparser doesn't know linenumbers, and the way wikitexthtml resolves templates at the moment doesn't make it possible to know which template generated the problem.

All in all, this is a hard problem to solve, but possibly worth the time.