PulsarCrossCorr_v2: fixed the output (E[rho]/h0^2)^2 in statistic function, removed double calculated (g_\alpha)^2 in metric components function.
XLALSimAddInjectionREAL8TimeSeries() XLALSimAddInjectionREAL4TimeSeries()

preformance improvement:  don't pad input time series if not doing
frequency-domain transformation

This reverts e3a9250f9deb92fd119cf70424e088b79167691b, re-applies
8c9f042607152fa699405a7579412efa385f8a63, but with a correction to the
index arithmetic to fix a thinko that was shortening the input time series.