ROADMAP.md: make it markdown formatted

docs/ROADMAP.md

+curl the next few years - perhaps
+=======================
+
+Roadmap of things Daniel Stenberg and Steve Holme want to work on next. It is
+intended to serve as a guideline for others for information, feedback and
+possible participation.
+
+New stuff - libcurl
+===================
+
+1. http2 test suite
+
+2. http2 multiplexing/pipelining
+
+3. SPDY
+
+4. SRV records
+
+5. HTTPS to proxy
+
+6. make sure there's an easy handle passed in to curl_formadd(),
+   curl_formget() and curl_formfree() by adding replacement functions and
+   deprecating the old ones to allow custom mallocs and more
+
+7. HTTP Digest authentication via Windows SSPI
+
+8. GSSAPI authentication in the email protocols
+
+9. add support for third-party SASL libraries such as Cyrus SASL - may need to
+   move existing native and SSPI based authentication into vsasl folder after
+   reworking HTTP and SASL code
+
+10. SASL authentication in LDAP
+
+11. Simplify the SMTP email interface so that programmers don't have to
+    construct the body of an email that contains all the headers, alternative
+    content, images and attachments - maintain raw interface so that
+    programmers that want to do this can
+
+12. Allow the email protocols to return the capabilities before
+    authenticating. This will allow an application to decide on the best
+    authentication mechanism
+
+13. Allow Windows threading model to be replaced by Win32 pthreads port
+
+14. Implement a dynamic buffer size to allow SFTP to use much larger buffers
+    and possibly allow the size to be customizable by applications. Use less
+    memory when handles are not in use?
+
+New stuff - curl
+================
+
+1. Embed a language interpreter (lua?). For that middle ground where curl
+   isn’t enough and a libcurl binding feels “too much”. Build-time conditional
+   of course.
+
+2. Simplify the SMTP command line so that the headers and multi-part content
+   don't have to be constructed before calling curl
+
+Improve
+=======
+
+1. build for windows (considered hard by many users)
+
+2. curl -h output (considered overwhelming to users)
+
+3. we have > 160 command line options, is there a way to redo things to
+   simplify or improve the situation as we are likely to keep adding
+   features/options in the future too
+
+4. docs (considered "bad" by users but how do we make it better?)
+   A - split up curl_easy_setopt.3
+   B - split up curl.1
+
+5. authentication framework (consider merging HTTP and SASL authentication to
+   give one API for protocols to call)
+
+6. Perform some of the clean up from the TODO document, removing old
+   definitions and such like that are currently earmarked to be removed years
+   ago
+
+Remove
+======
+
+1. cmake support (nobody maintains it)
+
+2. makefile.vc files as there is no point in maintaining two sets of Windows
+   makefiles. Note: These are currently being used by the Windows autobuilds