Resolve SPI-1481 "Arrow offline cmake"

Closes SPI-1481 Arrow no longer builds its dependencies on its own. These (notably Thrift) have now been added as formal dependencies. Thrift is built using the CMAKE recipe which was found in Arrow's source files, with some modifications. Some tweaks and optimizations are probably still possible. The package jemalloc is an exception to this solution, as Arrow wants to use a specific version in order to apply its own patches. This patched version is used by Arrow alone, and should not affect the rest of the stack. Source files for this version are now downloaded from AFS instead of the usual URL.

OpenSSL is listed as a dependency of Thrift in the official docs, but is taken implicitly from the system in our case. In the future it might be nice to state that OpenSSL is taken from system in the systemtools.cmake file, but this introduced minor breakage with m2crypto on slc6 this time.