v0.75b "Lazy Japanese Summer"

This version (v0.75b) can be installed by vsrepo.

Breaking change: it is discovered the v0.75b's default opt=1 (which uses int32 as intermediate type for as long as possible) might cause some issues when integer multiplication overflows int32 and wraps around, so v0.75b2 (file akarin-release-lexpr-amd64-v0.75b2-opt-0.7z) changes the default opt argument to 0 to disable automatic integer optimization. It's recommended that existing v0.75b users migrate to this patch release.

Changes:

1. @misakikasumi improved the vfx filters in the following aspects:

• performance can be improved significantly by setting appropriate num_streams>1
• support for RGB24 inputs, in addition to RGBS.
• support setting output_depth to select between 32 (RGBS) and 8 (RGB24) outputs; default to use the same format as the input clip.

2. lexpr added support for clip and clamp operators: x 16 235 clip and x 16 235 clamp are both equivalent to x 16 max 235 min.
3. It's determined that DLISR does not play well with other CUDA filters in the same script, so please make sure you only use cpu filters if you use DLISR in a script (shouldn't matter much as DLISR can saturate the highest end GPU easily so using other GPU filters will probably just slow things down)
4. (version v0.75b2) changes default opt parameter value to 0 forakarin.Expr as the default int32 optimization is known to cause issues for some of expressions.
5. (version v0.75b3) adds a unbounded cache for the compiled result, so script should reload much faster with Python based previewers. (Not ready yet, will crash at exit.)

Installation notes:

1. For DLISR, need to download https://github.com/AkarinVS/vapoursynth-plugin/releases/download/v0.70/akarin.dlisr.v1b.7z and place akarin.dlisr.dll alone side akarin.dll (this step is only necessary if you want to use DLISR)
2. For DLVFX, please see https://github.com/AkarinVS/vapoursynth-plugin/releases/tag/v0.70 on how to install required components.