SD.exists() has weird side effect

@fat16lib Thank you for noting to call rewindDirectory (I was having many issues with this) before using printDirectory.

I was trying to pass-through a modified library function that passes back file creation time, so I could convert it to a unix-time with timezone offset for comparing values. So I would call printDirectory to get a list of fileNames, then check creation date time. When I tried:

** if (!entryFile.dirEntry(&d)) {**
** Serial.println("Error Date");**
** }**

it would shift the position printDirectory started at and causes the first one to fail. Using the rewindDirectory before printDirectory fixed it though.