Support for Jasper's Encrypted Pre-Authentication Token

[ronindesign]

Hello @grantbacon

I improved session / cookie management in regards to pre-authentication via encrypted token.
Your cookie management improvements work great for storing the returned "Set-Cookie" header, but I believe there was no logic implemented to read or "set" these cookies on the curl handler for the next (or subsequent) calls to the jasper server. I've made a pull request on my implementation, I'd love to get it back into master so our project can revert back to using master for production rather than my fork.

Also, I'm not sure if the current curl implementation can handle the HTTP 301 redirect after the pre-authentication module finished validating the token and returns a JSESSIONID, looks like:

local server -> jasper (token in url) -> jasper pre-auth module (returns sessid) -> jasper REST (HTTP 301)

ref: http://community.jaspersoft.com/documentation/tibco-jasperreports-server-authentication-cookbook/v601/token-based-authentication

Please let me know if there would be a better technique or method for implementing this solution and I can update my code, then submit another PR. Thanks, I appreciate it.