src/processes.c: Importing changes from `main`.

src/processes.c: Importing changes from `main`.

Changes:
d47b7020743e0ef942401b8cf143a0ac6476f9f5 clang format
71e99e00e21c8181408b590929f856830deac732 Compare both PID and process start time to avoid issues with immediate PID reuse on Linux platform.
9197134e7cd99206900f86f660be2135d028a2ab processes: format array size def in read fork_rate & ctxt
a8b4168ac2237449e3192be3dd2d07ef587fa3e2 processes: fix prints & remove useless comments
2495f75ea8fc4ac0f295b0bdd38cb5eeb1ddd7c4 processes: eliminate hardcoded arraysize in read ctxt & fork_rate
d2626382c6f0c506993ec13c4c2bcd69bad19371 processes: determine if ctxt is enabled before read_sys_ctxt_switch
0c41886ca975ed679e568210caa743af6bb75678 processes: format `/proc/stat` WARNING & ERROR
7a262979f76ebb5868320e09107bc02dc101ff07 processes: use buffer to read /proc/stat once according to procs_running
ffc486a93f980b4d0d859b5f627f859d1877646c processes: remove running++ since we calc it in procs_running later
c3bbd17e13558b15e09f0ecb374e44dfbf3623cd processes: make contextswitches configurable
dfd034032b7c7c8f821774715c0723c42cefd332 Add scalloc() and use it in src/processes.c (#4014)