php53: fix on darwin

* add libssh2 to build inputs (configure fails without this)
* link with stdc++
* add icu/lib directory to DYLD_LIBRARY_PATH (and wrap binaries with this
  environment variable
* add libiconv to build inputs
* fix --with-iconv configure flag (was --with-iconv-dir which is not a valid
  flag)
php53: add optional pcntl flag
php53: restore nix gd version
php53-xdebug: add expression
update pulseaudio to 4.0 and sbc to 1.1
libcap needs to be a propagated build input for pulseaudio
kmplayer: update to 0.11.3d
kmplayer: minor fixes

Wrap mplayer into PATH
Remove unneeded dependency on gtk
qemu: Enable support for VDE networking
Linux 3.2-3.9: Add CONFIG_RC_DEVICES=y, to enable IR devices that can be used by lirc/devinput
Remove Firefox 20.0
firefox: Rename 21.0.nix to default.nix
firefox: Update to 22.0
Linux 3.2: Doesn't support CONFIG_RC_DEVICES option
avrdude: Add libusb to enable USB support
Merge pull request #677 from the-kenny/avrdude

avrdude: Add libusb to enable USB support
Fix reference to firefox21
add retroarch 0.9.9
String::ToIdentifier::EN: Update to 0.10
Making ccrtp propagate its build time requirement, ucommon.