[core] try to find xmlsec1 in the path
[core] whitespace cleanup
HUE-2458 [core] except libsaml.views.acs from csrf
HUE-2458 [core] Add support for configuring the SAML2 name id
HUE-2458 [core] Expose a POST logout URL

This is not backwards compatible with the old djangosaml2
HUE-2458 [core] make SAML2 urls backwards compatible
HUE-2458 [core] Fix the import order
HUE-2458 [core] simplify finding xmlsec binary
Use the PATH to find the xmlsec1 binary