Fix ignoring paths on rootcheck

[Zenidd]

The fix in this PR partially solves the issue #3030

• Now the check_dev module now ignores the paths specified in ossec.conf.
• The rest of the rootcheck modules( check_trojans, check_files, check_sys) that perform a search in the file system still do not implement the ignore functionality well.

[Zenidd]

The fix in this PR solves the issue #3030

• Now the check_dev module now ignores paths and files specified in ossec.conf.

• The rest of the rootcheck modules( check_trojans, check_files, check_sys..) that perform a search in the file system are now able to ignore path and files.

Tests have been performed ignoring paths and files in different locations of the file system.

[albertomn86]

Example of use:

• Using sregex:
  <ignore type="sregex">/dev/ignore/</ignore>

2019/04/23 11:20:15 ossec-syscheckd[46437] rootcheck.c:267 at check_ignore(): DEBUG: '/dev/ignore/.badalert' matches the '/dev/ignore/' pattern, so it will be ignored.

• Using full path:
  <ignore>/dev/ignore/.badalert</ignore>

2019/04/23 11:14:46 ossec-syscheckd[43323] rootcheck.c:275 at check_ignore(): DEBUG: '/dev/ignore/.badalert' has been marked as ignored.