Log, Files: improve performance when loading unchanged files (or delay load unchanged files)

File Filter search box in the File View is very very helpful to search file(s) quickly if there are thousands of

files in one project. After that we can do wanted operations in its context menu.

However, for large projects, e.g. Chromium, which has 300000+ files, SmartGit takes about 2+ seconds to change File View and Change View if i switch one commit to the other one in the Graph View. (Note: The chromium project is located on a super-fast NVME SSD; it must be much slower on SATAs).

Though I can change the low-level property "log.files.includeUnchanged" to false, it make file search unavailable. Besides, it is a global setting and cannot only be set to the chromium repo.

In my personal opinion, there is no need to load unchanged files right away. These unchanged files can be loaded in the background asynchronously.

Thanks a lot!