remove xbadpcm codec

supported in ffmpeg
remove asap

now an add-on
remove outdated entries
start removing mad
get rid of cstdstring in ifile interface
DNSNameCache: get rid of CStdString
callbacks: add function to utilize DNS cache
move defines to xbmc_addon_types.h instead of xbmc_addon_dll.h

xbmc_addon_dll.h cannot be included in more than one compile
unit
add URLEncode add-on callback
add AuthenticateURL addon callback
add support for vfs add-ons
add IDirectory callbacks for VFS addons
remove SFTP support

now an add-on
remove NFS support

now an add-on
remove internal rar support

now an add-on. still some code in core that is
specific to archives which cannot be removed.
temporary NFS hack
remove slingbox

now an (untested) add-on
disable filedirectories in addonbrowser

welcome back vfs.rar
remove hdhomerun

now an (untested) add-on
rebased on upstream

- fix broken test
- add new file