In the current router DSL, using the +match+ DSL
method will match all verbs for the path to the
specified endpoint.

In the vast majority of cases, people are
currently using +match+ when they actually mean
+get+. This introduces security implications.

This commit disallows calling +match+ without
an HTTP verb constraint by default. To explicitly
match all verbs, this commit also adds a
:via => :all option to +match+.

Closes #5964