Backport code snippets from pyrocore and pmp

[chros73]

Backport code snippets from pyrocore and pmp (thx to @pyroscope) and apply new commands of rtorrent-ps-ch:

• add new commands:
  • system.startup_time : Returns startup time
  • os.path.mtime : Get mtime of a path, return 2nd argument when path does not exist
  • d.timestamp.downloaded
  • d.timestamp.last_xfer, d.timestamp.last_active are renamed
• replace chars.* commands (chars.chop, chars.pad) with string.substr/string.shorten and string.lpad/string.rpad
• use d.tracker_alias command in logs (instead of d.tracker_domain)
• set network.history.auto_scale to 0 by default
• set pyrocore tools alias definitions
• scrape a little after completion in Auto scraping
• add last_xfer view
• make } and | keyboard shortcuts instant
• add new keyboard shortcuts
  • u : uptime command
  • _ : toggle specified extra columns (Elapsed time, Chunk Size)
• remove key bindings, they're built in rtorrent-ps-ch:
  • * toggle collapse views
  • / toggle visibility of certain columns

Remove:

• unused color schemes (they're now included in color-schemes dir of pyrocore)
• getElapsedTime.sh external script, use pyro._elapsed_time private method instead

Modify pyrocore config files:

• add sweep directives
• modify/add filelist, movehere, tag_show formats
• add aliases for public trackers
• add has_nfo, has_thumb, partial_info, tv_mapper, has_room custom fields

Update WIKI pages.

Notes: requires rtorrent-ps-ch v1.8.1-0.9.7