What I did was, in order:
Delete the package from package control.
Delete the Backup folder it creates (Just in case).
emerge (gentoo user here) the latest version of Clang and llvm (3.1-r4, the hardmasked one also works).
Copy both libclang and libLLVM-3.1 to the plugins main directory.
Use cmake to generate the configuration for libcache, and then make, wich built and linked the shared object for libcache.
Success. No more popup warnings whatsoever.
I beleave there should be an update on the github main comment as to reflex people to USE 3.1 instead of 3.0, since it has backwards compatibility.
Also, make a mention that under the CMakeFilelist fetched by package control, there is no mention for fetching, downloading or building libclang.
So building it is overdue to the user appart from building libcache.
Thanks in advice and hope this serves well for someone else.