Missing cstring include in buffer_curl.cpp

[chrisrichardson77]

May only apply to certain compilers, in this case gcc-4.9.

Build output:
g++ -Wall -mtune=core2 -march=core2 -msse3 -mfpmath=sse -m64 -O3 -c -o buffer_curl.o buffer_curl.cpp
buffer_curl.cpp: In function ‘JAD::Buffer* JAD::http_post_buffer(const char_, JAD::Buffer_, std::string&, const char*, int)’:
buffer_curl.cpp:87:32: error: ‘strtok’ was not declared in this scope
return_type = strtok(rt,";");
...