Revert "paplayer: use position based seeks for ffmpeg demuxer"

This reverts commit fdcb40a9c2817d87a661a7cb7d72808e0f09ffed.
paplayer: rewind stream after init (ffmpeg codec)
Merge pull request #4500 from FernetMenta/aefixes

Revert "paplayer: use position based seeks for ffmpeg demuxer"
settings: fix detection of value changes in CSettingList
[webui] Add keyboard controls to web remote
Merge pull request #4508 from Montellese/settinglist_default_fix

settings: fix detection of value changes in CSettingList
Merge pull request #4494 from davidbanham/master

Add keyboard controls to web remote
Merge pull request #4504 from FernetMenta/paplayer

paplayer: rewind stream after init (ffmpeg codec)
Factor out querying user to remote missing path
Add version of URIUtils::IsInPath that takes a vector of baseURIs
Fix glacial video library cleanup with missing sources

Test whether our sources are accessible right up front during library
cleanup.  If they're missing and the user wants to remove their
contents, avoid stat() calls where possible using string compares. This
saves us, for instance, on SMB where CFile::Exists() times out for every
file and path.
Fix slow library update when sources are unavailable.

Similarly to the fixes for clean library, avoid stat() calls by testing
the source's existence and doing string comparisons during scan.