value is missing or set to 0 in the sbbs.ini file, the sanity checking this
value (setting it to 2 seconds) will not occur after a server recycle and the
sbbs.ini is re-parsed. So if for any reason, the sem_chk_freq value becomes
0, these server threads won't hog the CPU because they all YIELD at the
top of thier main loops.

Also, changed all the thread names (e.g. adding "sbbs/" prefix), so they're
more sensible in the Linux 'top' output.

Also, started adding 'vi' modelines to auto-set tabstops when using vi/vim.