+ compilation time. Use --cfg=contexts/factory:raw for maximal speed.
+ * Add an option --cfg=contexts/stacksize:N to set the stack size of the user
+ contextes at runtime (only with raw contexts or ucontexts).
+ * Completely rewrote this module to allow parallel execution of user
+ processes. Use --cfg=contexts/nthreads:N to execute user processes
+ with N parallel threads (the default is 1, meaning no parallelism).
+ * Allow to decide dynamically between sequential and parallel modes.
+ When nthreads > 1, you can use --cfg=contexts/threshold:P to run the user
+ processes in parallel only when their number is greater than or equal to P
+ (the default is 2).
+ * Added a check for NaN of IEEE754 infinite in the double entries of
+ the smx_user.c file