Add RAVL tree for Coarse Provider

Add RAVL tree for Coarse Provider.
The code of RAVL tree comes from
https://github.com/pmem/pmdk

Signed-off-by: Lukasz Dorau <[email protected]>

Author: ldorau

src/CMakeLists.txt

@@ -84,6 +84,7 @@ set(UMF_SOURCES
     memspace.c
     provider/provider_tracking.c
     critnib/critnib.c
+    ravl/ravl.c
     pool/pool_proxy.c
     pool/pool_scalable.c)