DOC: remove the outdated ROADMAP file

It's almost never update (last time was 3 years ago) and contains both
stuff that was already implemented and stuff that nobody's interested in
anymore. Let's remove it.
diff --git a/.gitignore b/.gitignore
index ef880c3..d588b07 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,7 +15,6 @@
 !/INSTALL
 !/CONTRIBUTING
 !/MAINTAINERS
-!/ROADMAP
 !/SUBVERS
 !/VERDATE
 !/VERSION
diff --git a/ROADMAP b/ROADMAP
deleted file mode 100644
index a797b84..0000000
--- a/ROADMAP
+++ /dev/null
@@ -1,76 +0,0 @@
-Medium-long term wish list - updated 2019/06/15
-
-Legend: '+' = done, '-' = todo, '*' = done except doc
-
-2.1 or later :
-  - return-html code xxx [ file "xxx" | text "xxx" ] if <acl>
-
-  - return-raw  [ file "xxx" | text "xxx" ] if <acl>
-
-  - have multi-criteria analysers which subscribe to req flags, rsp flags, and
-    stream interface changes. This would result in a single analyser to wait
-    for the end of data transfer in HTTP.
-
-  - make it possible to condition a timeout on an ACL (dynamic timeouts)
-
-  - forwardfor/originalto except with IPv6
-
-  - tcp-request session expect-proxy {L4|L5} if ...
-
-  - wait on resource (time, mem, CPU, socket, server's conn, server's rate, ...)
-
-  - bandwidth limits
-
-  - buddy servers to build defined lists of failovers. Detect loops during
-    the config check.
-
-          server XXX buddy YYY
-          server YYY    # may replace XXX when XXX fails
-
-  - spare servers : servers which are used in LB only when a minimum farm
-    weight threshold is not satisfied anymore. Useful for inter-site LB with
-    local pref by default.
-
-  - add support for event-triggered epoll, and maybe change all events handling
-    to pass through an event cache to handle temporarily disabled events.
-
-  - evaluate the changes required for multi-process+shared mem or multi-thread
-    +thread-local+fast locking.
-
-Old, maybe obsolete points :
-  - clarify licence by adding a 'MODULE_LICENCE("GPL")' or something equivalent.
-
-  - 3 memory models : failsafe (prealloc), normal (current), optimal (alloc on
-    demand)
-
-  - verify if it would be worth implementing an epoll_ctl_batch() for Linux
-
-  - option minservers XXX : activates some spare servers when active servers
-    are insufficient
-
-  - initcwnd parameter for bind sockets : needed in kernel first
-
-  - have a callback function which would be called after a server is selected,
-    for header post-processing. That would be mainly used to remove then add
-    the server's name or cookie in a header so that the server knows it.
-
-Unsorted :
-  - internal socket for "server XXX frontend:name"
-
-  - XML inspection (content-switching for SOAP requests)
-
-  - random cookie generator
-
-  - fastcgi to servers
-
-  - hot config reload
-
-  - RHI - BGP
-
-  - telnet/SSH cli
-
-  - dynamic memory allocation
-
-  - dynamic weights based on check response headers and traffic response time
-
-  - various kernel-level acceleration (multi-accept, ssplice, epoll2...)