Comment 3 for bug 905669

Cool -- I thought we did use mtimes but it turns out we don't! This is some low-hanging fruit. All that has to be done is to update the folder hash calculation in src/library/libraryscanner.cpp in the recursiveScan() method. We test whether to rescan a directory by concatenating all the filenames of the files in it and hashing it and comparing it against a previous hash. If you just append the mtime to the filename, that would be good enough to cause the directory to be rescanned.