Build tools directory
autogen.sh: remove call to configure
Fix docs build
gitignore: ignore more files
configure: remove "Hidden visibility" note at end
Add pkg.m4
Use libpng instead of libpng12 for pkg-config name
Updating od_state_ref_imgs_init() to allocate OD_UMV_PADDING around io_imgs.
Renaming daala_encode_alloc() to daala_encode_create().
Fixes unused variable warnings
Add some things to git ignores.
Decoder perfect reconstruction for (at least) subset1/subset3.

Easiest way to avoid problems with inconsistent float rounding breaking
 the (temporary!) horrible float quantization code is to execute exactly
 the same code in the encoder and the decoder.

This was the approach that I originally took in my out of tree decoder work,
 and I've switched back to it as it just works and any additional time
 invested here should probably just be put into replacing the PVQ quantizer
 with a fixed-point version.