this commit only addresses the analysis sub-package
With this change, TermLocations are computed and maintained only if includeTermVectors is enabled, for higher performance.
benchmark old ns/op new ns/op delta BenchmarkAnalysis-4 1599218 1540991 -3.64% benchmark old allocs new allocs delta BenchmarkAnalysis-4 5353 5318 -0.65% benchmark old bytes new bytes delta BenchmarkAnalysis-4 370495 362983 -2.03%