Ability to change the list of files at any time, including through UI (#115)

* Now can update the list of files without pausing/unpausing

* Shrink a few functions

* Reopen write when updating files

* Todos

* opened_file abstraction

* iter_pieces_within iterator

* Simplify iter_pieces_within

* Simplify iter_pieces_within

* Add "iter_file_details"

* temporarily broken: readonly by default

* Live torrent - reopen files

* Reopen files after changing the list

* Now reopening files read only when they are completed

* Fix a bug in opened_file.rs

* update todos

* update help

* Reconnect all peers that are idling

* Add a couple fields to OpenedFile

* Add a couple fields to OpenedFile

* Small cleanups - use the new iterator where possible

* size_of_piece_in_file function

* Updating have

* Include file progress

* Almost nothing

* ugly progress bars

* bad UI, saving

* its not so bad

* Works now

* update progress bar a bit

* Reopen read-only on pause

* Zero bytes isnt too bad! Doesnt break anything

* fix per file progress bars

* progress bar not as ugly anymore?

* ui tweaks

* fix a react bug

* TODO.md update

* Fix js + TODOs

* Compute per-file progress on init

* Fix stats updating live

* Nothing

* Nothing

* cleanup ui a bit

* Nothing

* Final fixes

* Trying to fix rust 1.73

* Sorting filenames

* remove unnecessary indentation

* Remove unnecessary comment

TODO.md

@@ -68,3 +68,18 @@ refactor:
 - [x] checking is very slow on raspberry
       checked. nothing much can be done here. Even if raspberry's own libssl.so is used it's still super slow (sha1)
 - [ ] .rqbit-session.json file has 0 bytes when disk full. I guess fs::rename does this when disk is full? at least on linux. Couldn't repro on MacOS
+
+- reopen:
+
+  - [x] in general, the only time the file should be write-only, is when it's live and not yet fully downloaded
+  - [x] initializing: open read-only if file has all pieces
+  - [x] on piece validated open read-only all files that were copleted
+  - [x] would be nice to have some abstraction that walks files and their pieces
+  - [ ] nit: optimize open write/read/write right away on first start
+  - [x] peers: if finished they are all paused forever, but if we change the list of files, we need to restart them
+
+- [x] opened_files: track HAVE progress
+  - [x] actually track
+  - [x] show in API and UI
+  - [x] refresh when downloading (it doesn't somehow)
+  - [x] on restart, this is not computed, compute