Mark 11 release in the changelog

Also fix some typos in the entries for the 11 release.

(cherry picked from commit d9792b7735)
Signed-off-by: Diego Biurrun <diego@biurrun.de>

Changelog

@@ -1,7 +1,7 @@
 Entries are sorted chronologically from oldest to youngest within each release,
 releases are sorted from youngest to oldest.
 
-version <next>:
+version 11:
 - libx265 encoder
 - shuffleplanes filter
 - replaygain data export
@@ -9,7 +9,7 @@ version <next>:
 - BRender PIX image decoder
 - Amazing Studio PAF playback support
 - XBM decoder
-- bmp standalone parser
+- BMP standalone parser
 - OpenEXR image decoder
 - support encoding and decoding 4-channel SGI images
 - support decoding 16-bit RLE SGI images
@@ -26,12 +26,12 @@ version <next>:
 - support for decoding through DXVA2 in avconv
 - libbs2b-based stereo-to-binaural audio filter
 - native Opus decoder
-- display matrix export and rotation api
+- display matrix export and rotation API
 - drop avserver, it was unmaintained for years and largely broken
 - Icecast protocol
-- request icecast metadata by default
+- request Icecast metadata by default
 - support for using metadata in stream specifiers in avtools
-- matroska 3d support
+- Matroska 3D support
 
 
 version 10: