ReleaseNotes: add two more noteworthy entries

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

installer/ReleaseNotes.md

@@ -43,6 +43,8 @@ This package contains software from a number of other projects including Bash, z
 * The `connect.exe` tool to allow SSH connections via HTTP/HTTPS/SOCKS proxies [is included in Git for Windows again](https://github.com/git-for-windows/build-extra/pull/73), as it was in Git for Windows 1.x.
 * The `LANG` variable is [no longer left unset](https://github.com/git-for-windows/git/issues/298) (which caused troubles with vim).
 * `call start-ssh-agent` [no longer spits out bogus lines](https://github.com/git-for-windows/git/issues/314).
+* It is now possible [even behind NTLM-authenticated proxies](https://github.com/git-for-windows/git/issues/309) to install [Git for Windows' SDK](https://git-for-windows.github.io/#download-sdk).
+* We [can handle the situation now](https://github.com/git-for-windows/git/issues/318) when the first `$PATH` elements point outside of Git for Windows' `bin/` directories and contain `.dll` files that interfere with our own (e.g. PostgreSQL's `libintl-8.dll`).
 
 ##Changes since Git-2.4.6 (July 18th 2015)