LD_RUNPATH_SEARCH_PATHS

Add @rpath to LD_RUNPATH_SEARCH_PATHS so the library will properly be
found within app bundles
Make ADAuthenticationBroker.h public

Needed so external clients can tell ADAL when auth has been cancelled.
synthesize webView for OS X

Fixes an OS X crash
Delete Cookies after authentication finishes

Leaving cookies around in the shared cookie store breaks multiple user
scenarios as the web client only supports a single client signed in at
a time.
Add build products to .gitignore