Analysis may be incorrect depending on timing/module load order

[MikhailArkhipov]

When analyzing mod1 that imports mod2 code in

            var reanalyzeEntries = aliases.SelectMany(a => Analyzer.GetEntriesThatImportModule(a, true)).ToArray();
            foreach (var entryRef in reanalyzeEntries) {
                await EnqueueItemAsync(entryRef as IDocument, AnalysisPriority.Low, parse: false);
            }

assumes that analysis of other modules is complete and GetEntriesThatImportModule will return the correct set. However, if analysis of dependencies hasn't been completed yet, the set may be incomplete. So in find reference tests code that loads dependency first like

                var uri2 = await TestData.CreateTestSpecificFileAsync("mod2.py", text2);
                using (server.AnalysisQueue.Pause()) {
                    await server.LoadFileAsync(uri2);
                    uri1 = await server.OpenDocumentAndGetUriAsync("mod1.py", text1);
                }

will succeed because mod2 will be placed in the queue first, but code that loads dependency last

                var uri2 = await TestData.CreateTestSpecificFileAsync("mod2.py", text2);
                using (server.AnalysisQueue.Pause()) {
                    uri1 = await server.OpenDocumentAndGetUriAsync("mod1.py", text1);
                    await server.LoadFileAsync(uri2);
                }

will lead to incomplete analysis with references missing

[MikhailArkhipov]

This requires fair amount of work to build dependency graph and re-analyze from there.

[MikhailArkhipov]

#135