also:
 o remove dead code, create_dummy_frame
 o Fix a bug in command line handling that caused a segfault if wrong
   number of arguments were given.

Change-Id: I78f026aee4e363967b750e6cde0982659c558a1f

Modifications to the spatial scalable encoder to match
changes made to the scaling code in the decoder.

In particular, the use of a dummy first frame was removed
now that the decoder is able to handle a smaller first
frame.

SvcTest.FirstFrameHasLayers unit test re-enabled.

Change-Id: Ic2e91fbe4eadf95895569947670d36d68abaf458

- Move IVF reading support into ivfdec.c and ivfdec.h
- Move IVF writing support into ivfenc.c and ivfenc.h
- Removed IVF writing code from the SVC example in favor of ivfenc.

Change-Id: I70adf6240d0320fdd232d8546ed573f0f68dd793

SVC multiple layer per frame encoding is invoked with vpx_svc_init and
vpx_svc_encode. These interfaces are designed to be invoked from ffmpeg.
Additional improvements:
- make dummy frame handling a bit more explicit
- fixed bug with single layer encodes
- track individual frame sizes and psnrs instead of averages
- parameterized quantizer, 16th scalefactors, more logging,
- enabled single layer encodes to generate baseline
- include new mode for 3 layer I frame with 5 total layers

Change-Id: I46cfa600d102e208c6af8acd6132e0cc25cda8d4

This reverts commit a82001b1, reversing
changes made to f6d870f7.

This commit breaks windows builds and needs some work to fix those and
some additional comments.

Change-Id: Ic0b0228e36704b127e5e399ce59db26182cfffe7

These changes were originally made in the Stratacaster team-review repository

commit e114bffcd82ad74c3696ec58e13c0ac895d6c82d
Author: Charles 'Buck' Krasic <ckrasic@google.com>
Date:   Mon Oct 14 16:52:13 2013 -0700

    Make dummy frame handling a bit more explicit, fixing bug
    with single layer encodes.

Squashed commit of the following:

commit 1ebbfd976c0fadb02bf1ea562a2d0e3f0206daad
Merge: ac468dde 54e88b7
Author: Ivan Maltz <ivanmaltz@google.com>
Date:   Fri Oct 11 17:29:58 2013 -0700

    Move SVC code from vp9_spatial_scalable_encoder to libvpx module accessible from ffmpeg

commit 54e88b78b160becc9569fc3c6cb6b0a8c95dc357
Author: Ivan Maltz <ivanmaltz@google.com>
Date:   Tue Oct 8 09:08:40 2013 -0700

    common svc encoding code for sample app and ffmpeg

    added svc_encodeframe.c, svc_context.h, svc_test.cc

    vp9_spatial_scalable_encoder uses vpx_svc_encode

commit 5616ec8e2e3d3e8d277333d8a9242f6c70151162
Merge: 4528014 e29137df
Author: Ivan Maltz <ivanmaltz@google.com>
Date:   Tue Oct 8 08:47:58 2013 -0700

    Merge branch 'master' into stratacaster

commit 45280148450b1f3d61e390df8aadedf85cd5bce1
Merge: bb2b675 1ab60f7b
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Fri Oct 4 10:22:31 2013 -0700

    Merge branch 'master' into stratacaster

commit bb2b675e595dc9bfc8551e963edf56800c3aea61
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Wed Oct 2 12:37:26 2013 -0700

    Track individual frame sizes and psnrs instead of averages.

commit c6d303b714795c81e7ceb4173967115c9f8ff5b7
Merge: fa87df9 35830879
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Fri Sep 27 10:05:35 2013 -0700

    Merge branch 'master' into stratacaster

commit fa87df94fba923d9f7aeb8ae20c6e15f777e00b5
Merge: bf22d71 3c465af2
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Thu Sep 26 16:10:31 2013 -0700

    Merge branch 'master' into stratacaster

commit bf22d7144895a82e0c348ac177c8a261b9e2b88e
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Thu Sep 26 11:10:34 2013 -0700

    Parameterized quantizer, 16th scalefactors, more logging, enabled single layer encodes to generate baseline.

commit ceffd7e6025b765f9886b5ea0f324248aa37e327
Author: Sujeevan Rajayogam <sujee@google.com>
Date:   Thu Sep 19 10:04:49 2013 -0700

    - Include new mode for 3 layer I frame with 5 total layers.
    - Refactor svc api.

Change-Id: Ie4d775e21e006fa597d884c59488dc999478e9b5

Sample app: vp9_spatial_scalable_encoder
vpx_codec_control extensions:
  VP9E_SET_SVC
  VP9E_SET_WIDTH, VP9E_SET_HEIGHT, VP9E_SET_LAYER
  VP9E_SET_MIN_Q, VP9E_SET_MAX_Q
expanded buffer size for vp9_convolve

modified setting of initial width in vp9_onyx_if.c so that layer size
can be set prior to initial encode

Default number of layers set to 3 (VPX_SS_DEFAULT_LAYERS)
Number of layers set explicitly in vpx_codec_enc_cfg.ss_number_layers

Change-Id: I2c7a6fe6d665113671337032f7ad032430ac4197