dvr: rewrite to use the idnode system
channel: cleanup the configuration tree

  <cfg>/channel/config
  <cfg>/channel/tag

Also use hts_settings_load() instead hts_settings_load_r() for
the appropriate places..
config migration: check for old filenames in the config dir
config migrate: run check only when version changed
dvr autorec: fix a memory leak
epggrab: channels - fix memory leak
subscription: Fix a memory leak in link service
DVR: api - fix the dvr config entry create perm check
ACL/DVR: Rewrite channel tag and add DVR config selection

- remove also obsolete only_tag
- accept only uuid for DVR entry config name
- try to lock DVR entry when used in dvr_thread
WEBUI: add possibility to override column width for grid

- also improve the ACL edit window
DVR: autorec duration fixes
comet events - an attempt to clean them
WEBUI JS: remove all events from comet

- they are all used dynamically
WEBUI JS: remove comet debug log console messages
WEBUI JS: root panel cleanups, ancient file removal
http: optimize the access verification
WEBUI JS: Add possibility to create tab panels dynamically (disabled by default)
WEBUI JS: add dynamic support to the idnode_tree
WEBUI JS: fix the status.js indentions
WEBUI JS: updated status tab to the dynamic behaviour