* disable jemalloc on windows (cannot run ./configure)
* disable jemalloc on ancient cmake (ExternalProject does not work)
* rewrite TokuDB compiler test to check for features, not versions (to work on cmake before 2.8.11)
* fix ft-index to not add VALGRIND_INCLUDE_DIR to includes, if no valgrind was found
* correct the package name in FindValgrind.cmake (for find_package(... REQUIRED) to work)
* disable ft-index tests by default (faster compilation and they aren't used anyway)
* don't build ft-index with valgrind by default (otherwise it *requires* valgrind, it doesn't auto-detect)
* use --loose-tokudb in the .opt file