avoid chrono dependency, depend on proxmox 0.3.8

- remove chrono dependency

- depend on proxmox 0.3.8

- remove epoch_now, epoch_now_u64 and epoch_now_f64

- remove tm_editor (moved to proxmox crate)

- use new helpers from proxmox 0.3.8
  * epoch_i64 and epoch_f64
  * parse_rfc3339
  * epoch_to_rfc3339_utc
  * strftime_local

- BackupDir changes:
  * store epoch and rfc3339 string instead of DateTime
  * backup_time_to_string now return a Result
  * remove unnecessary TryFrom<(BackupGroup, i64)> for BackupDir

- DynamicIndexHeader: change ctime to i64

- FixedIndexHeader: change ctime to i64

src/api2/reader.rs

@@ -1,4 +1,3 @@
-//use chrono::{Local, TimeZone};
 use anyhow::{bail, format_err, Error};
 use futures::*;
 use hyper::header::{self, HeaderValue, UPGRADE};
@@ -88,7 +87,7 @@ fn upgrade_to_backup_reader_protocol(
 
         //let files = BackupInfo::list_files(&path, &backup_dir)?;
 
-        let worker_id = format!("{}_{}_{}_{:08X}", store, backup_type, backup_id, backup_dir.backup_time().timestamp());
+        let worker_id = format!("{}_{}_{}_{:08X}", store, backup_type, backup_id, backup_dir.backup_time());
 
         WorkerTask::spawn("reader", Some(worker_id), userid.clone(), true, move |worker| {
             let mut env = ReaderEnvironment::new(