Add Socket Libraries.

Add Posix functions for porting compatibility.
Fix compliance issues with ISO/IEC 9899:199409
New Functions:
  setenv(), fparseln(), GetFileNameFromPath(), rename(),
  realpath(), setprogname(), getprogname(), strlcat(), strlcpy(),
  strsep(), setitimer(), getitimer(), timegm(), getopt(), basename(),
  mkstemp(), ffs(), vsnprintf(), snprintf(), getpass(), usleep(), select(),
  writev(), strcasecmp(), getcwd(), chdir(), tcgetpgrp(), getpgrp(), gettimeofday(),
  bcopy(), 


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12061 6f19259b-4bc3-4df7-8a09-765794883524

StdLib/LibC/String/String.inf

@@ -33,6 +33,9 @@
   Searching.c
   ErrorList.c
   strncasecmp.c
+  strlcpy.c
+  strlcat.c
+  strsep.c
 
 [Packages]
   StdLib/StdLib.dec