Attempt to find libjansson via pkg-config if AC_CHECK_LIB fails
Try to find jansson via pkg-config first, and fall back to checking system defaults if that fails
pool_active: Ensure temporary curl is always cleaned up
Update scrypt readme re drivers and sdk.
Merge commit '15f52a9' into bfgminer-2.10.x
Merge commit '4f13128' into bfgminer-2.10.x
fixed typo