haproxy-devel, 1.5dev21, multiple certs for 1 frontend, no default_backend if acls used, agent-check, html cleanup

-use new 1.5dev21 binaries.
-ability to NOT have a default_backend (if all frontends in a group use acl's)
-allow selecting multiple certificates for a single frontend
-support for configuring new 'agent-check'
-refactoring of html row_helper(), javascript table editing, field definition
-create 'valid' HTML (closing tags/javascript blocks/styles in head)