Added mechanism to add tracers information to the xparts. Added the EAGLE tracers (max(T) and time of max(T)). Tracers are dumped in snapshots.

Can still use the command-line --enable-option-checking to override this

Makes the assumption that -isystem and -Wstrict-prototypes are always available together, not sure that will always be true, but better than always assuming -isystem is

Move tic/toc out of SWIFT_DEBUG_TASKS sections, but keep the --enable-task-debugging configure option as that also requires another two fields that we don't otherwise need

Switch to only using ticks for repartition weights, avoid the problem of early repartitioning by not doing that, the memory balance initial partition is good enough to start with

Also remember to use srcdir when locating files