rdcost: use less fractional bits for lambda scale, and larger ints for chroma

This fixes really bad mode decisions made with some Main10 encodes that were
apparently caused by integer overflow

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branch : stable
fix g_chromaScale for 420 videos accordingly to the HEVC spec.

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branch : stable
interlace: set sourceScanType to 0 to indicate interlaced video

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branch : stable
extra : source : f3585fd81c3b94f8b1757d8fa3d60860b581e19c
Added tag 1.0 for changeset cea97c4d7945

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branch : stable