Merge pull request #8 in BIDU/software from 6links_slc_tool to 6links

* commit 'f00ba0c1':
  remove monitoring of slc fifo
  remove exec files
  remove editting files
  add status of links on statlink
  48 links for slow control library
  Fix compilation for CentOS8
  Change some log messages.
  Check if the next event's 7f7f magic word and, if not, wait until it appears.
  Modiry the output of pcie40_ul.
  Test other ports
  Debug slow control
  Fix resync function
  Update for 4 link version
  change names of variables
  Add argument to specify the link number
  Improve data checking program