Feature request: Nice way to handle image renames for sequential photos with the same EXIF timestamp

[Alexey Balmashnov]

Rationale:
Photo cameras are able to do more than one shot per second. Therefore, recorded images end up having the same timestep in EXIF metadata.

Current solution:
By default Pyrenamer appends original file name to a new name based on a timestamp, which is of course working. One may even come up with a way to strip out some infomation from the original file name using available group matching patterns, since the names of the images usually have "{L}_{#}.file_extension" format.

Proposition:
Teach Pyrenamer to recognize series of images with the same timestamp and provide functionality to nicely rename the series of shots, e.g. it would be nice to be able to do something like the following:
IMG_1234.JPG -> 20100308_12_00_01.JPG
IMG_1235.JPG -> 20100310_13_07_08.JPG
IMG_1236.JPG -> 20100310_14_06_51_1.JPG
IMG_1237.JPG -> 20100310_14_06_51_2.JPG
IMG_1238.JPG -> 20100310_14_06_51_3.JPG
IMG_1239.JPG -> 20100310_16_07_55.JPG

Thanks.