prompt handler: check for index error before requesting caption | vaecache: more robust handling of batched encoding | vaecache: fix for trailing slash existing in cache_dir property resulting in excessive scans at startup | bucket manager: cheaply remove duplicate images from the dataset during sorting | aspect bucketing: modify precision of bucket categories to 3 decimals from 2, this might require re-caching aspect buckets and VAE outputs | sd2.x: LoRA training fixes, still not quite right, but better | DoRA: initial support from PEFT integrated for XL and legacy models. #320