Calculations for delta.pitch and delta.field differ from previous calculations

I compared running `makeWAR()` on the May data set to the MayProcessed data set and noticed that the `delta.field` and `delta.pitch` columns in the New MayProcessed data set differed from the original MayProcessed data set. They actually look transposed which you can see below. I did this using `dplyr 0.5.0`, but I first noticed it when testing `makeWAR()` after refactoring for `dplyr 0.7.0` .

```
>NewMayProcessed <- makeWAR(May)
>head(NewMayProcessed$openWARPlays[,c(1:5,16, 19:23)])
batterId start1B start2B start3B pitcherId gameId delta delta.field delta.pitch delta.br delta.bat
1 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.3789624 NA 0.37896244 NA 0.3789624
2 519083 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.2055008 -0.04671768 -0.15878313 0.03238909 -0.2378899
3 452234 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.3296470 NA -0.32964703 0.04026076 -0.3699078
4 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.2032371 0.11692098 0.08631608 -0.53123407 0.7344711
5 518626 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.1956572 NA 0.19565721 -0.01790497 0.2135622
6 474384 518626 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.7097701 -0.36090191 -0.34886821 0.01234560 -0.7221157

> head(MayProcessed$openWARPlays[,c(1:5,16, 19:23)])
batterId start1B start2B start3B pitcherId gameId delta delta.field delta.pitch delta.br delta.bat
1 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.3789624 NA 0.3789624 NA 0.3789624
2 519083 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.2055008 -0.1588469 -0.0466539 0.03238909 -0.2378899
3 452234 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.3296470 NA -0.3296470 0.04026076 -0.3699078
4 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.2032371 0.1169279 0.0863092 -0.53123407 0.7344711
5 518626 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 0.1956572 NA 0.1956572 -0.01790497 0.2135622
6 474384 518626 493316 476704 450351 gid_2013_05_01_anamlb_oakmlb_1 -0.7097701 -0.3487953 -0.3609748 0.01234560 -0.7221157
```

The original MayProcessed data set was added over 2 years ago, and there have been quite a few changes to `makeWAR()` since then. I imagine this happened when `openWAR` and dplyrized. I'm pretty sure it has to do with [Line 140].(https://github.com/beanumber/openWAR/blob/master/R/makeWAR.R#L140)

```
x$data <- mutate_(x$data, delta.pitch = ~ifelse(is.na(delta.field), delta, delta - delta.field))
```

So I guess it boils down to which data set is correct? Is it the original MayProcessed data set?

Start with R/makeWAR.R at line 140 and reproduce the May versus MayProcessed comparison using makeWAR(). Trace how delta.field and delta.pitch are calculated, then determine which dataset reflects the intended calculation. Done means the expected column values are established and the implementation or data discrepancy is resolved and verified.

Written by the indexing model from the issue text.