Removed wma from recording mode shortcuts

WMA is still supported, but must be configured specifically, e.g.,
with --radiomode=wma.  Previous default behaviour may be enabled with
--modes=default,wma.
Web PVR: replace logo image with text
Fixed potential quoting problem with --command
Added support link to readme
Log error message and exit if output directory cannot be created

Provides a cleaner exit if directory creation fails.  Mainly for the
benefit of GUI wrappers.
Handle multiline subtitles
Remove schedules for Radio 1 regional variants
Man page changes for 55824fa (removed wma from mode shortcuts)
Added --subsrequired option

If --subsrequired is specified, programme will not be downloaded if
subtitles are not available.
Changed wording of --future description

Inserted "Additionally" to indicate future schedule is searched in
addition to current programmes.
Revert "Handle multiline subtitles"

This reverts commit f495e0d6df5a829c8b1aaa8c3b7e979066e0f1bc.
Subtitle fixes and new formats

Added support for multiline subtitles. (h/t J Larmour)
Fixed small timing error. (h/t R Dixon)
Added --subsfmt to select subtitles format

Possible values for --subsfmt:

default (or --subsfmt omitted):  Line break followed by leading
hyphen demarcates change in speaker.  All other line breaks removed,
so lines must be wrapped by media player.  Text rendered in default
subtitle colour for media player.

compact: Leading hyphen (without line break) demarcates change in
speaker.  All line breaks retained.  Text rendered in default subtitle
colour for media player.
Man page fix for --subsfmt
Man page fix for --subsfmt (corrected)
Added check for empty subtitles
Added validation for --subsfmt

If --subsfmt value is invalid, warning is generated and default
subtitles format is used.
Tag version 2.84
Windows Installer 4.6
Windows Installer 4.7
Update subtitle parsing to support explicit namespace