<issue_start><issue_comment>Title: Add support for command line arguments via getopt
username_0: Add support for command line arguments (via getopt) to run_yextend. This way the command line arguments can handled in a looser way than by strict index numbers. So for instance I want to be able to run like this:

./run_yextend -r x.yara -t file1

or 

./run_yextend --ruleset x.yara --target file1<issue_closed>
<issue_comment>username_1: We now have support for command line arguments via getopt