add getters

Hi

The autoNTLMAuthorization(...) method of net.lightbody.bmp.proxy.http.BrowserMobHttpClient class is not accessible. For limiting code in BrowserMob i have create this patch for accessing to the DefaultHttpClient with a getter.
The attributes of browsermob-proxy are private and it's difficult to add specific functionnality. It should be better if attributes are protected or if for each attribute there is the getter/setter

Thanks
Sylvain