Improve option parsing

[keithc-ca]

The primary change is to do option pattern matching just once. Instead of:

if ( $argv =~ /^\-\-graphSpecs=/ ) {
    ($graphSpecs) = $argv =~ /^\-\-graphSpecs=(.*)/;
}   

we can use:

if ( $argv =~ /^--graphSpecs=(.*)/ ) { 
    $graphSpecs = $1;
} 

which ensures a proper option match and captures the option value at the same time.
Also, - doesn't need to be escaped in this context.

[renfeiw]

LGTM. It's a cleaner and properer way of doing the argument parsing.

[smlambert]

Tested via Grinder (internal due to issues with openj9 Jenkins server today).