[dxvahd] attempt to fix colour range
Don't keep temp CReadState on CurlFile::Seek

Apparently there are a lot of servers around that limit to two
concurrent connections.  This also eliminates a potential leak of the
temporary CReadState should the early return be taken.
Try CurlFile::Seek without multisession on failure
Minor refactor of CurlFile::Seek
Merge pull request #4546 from t-nelson/curl_no_more_than_two_in_multi

Curl multi-session fixes
fix album rating wasn't saved in the database
Merge pull request #4573 from jmarshallnz/dxva_yuv_range_fix

[dxvahd] attempt to fix colour range
fixed: Downloading subs for rars was broken
Merge pull request #4572 from arnova/rar_subs

fixed: Downloading subs for rars was broken