[LLMeshRepo sync] Change camelcase LLConvexDecomp to lowercase, so mergetool is happy~
[LLMeshRepo sync] AICurl updates toward LLCurl

LLHTTPClient::getByteRange no longer throws AICurlNoEasyHandle, instead it returns whether or not it threw, to match the true/false convention of LLCurl.
- In addition, the header param has been shifted to earlier in this function to ease diffings.
ResponderBase now has static bool isGoodStatus, introduced into the Responder base class of LLCurl