Update with fixes for Yosemite & Shellshock test

Cleaned up OS version detection to use "as number" for clarity and accuracy.

Specified a single "OK" button on dialogs that didn't need a cancel button.

Added Yosemite SWUpdate URL.

Added a "target file" variable in the reset functions to gracefully handle using either the ".bashrc" or ".profile" as needed by the OS version.

Restored the missing "current user" text insert in the resetThisUserCPU() function. This was causing it not to actually specify the user account to delete, so it wasn't deleting anything.

Added testing for several Shellshock vulnerabilities, although currently it does nothing to resolve.

Added Yosemite-specific command to  FlushDNSCache()