autoconf: add --disable-wic

this allows windows builds to prefer libjpeg, libpng etc. for import and
export

Change-Id: Ibe1648b68a3f7b5016044e82530843dea46a94a4
cwebp: print metadata stats when no output file is given

this is more consistent with the encode stats

Change-Id: I5793062b3b29f5cb891461d6faaa53b43c0a4482
Only compute quantization params once

(all quantization params #1..#15 are the same)

Change-Id: If04058bd89fe2677b5b118ee4e1bcce88f0e4bf5
Make Forward WHT transform use 32bit fixed-point calculation

This is in preparation for a future change where input will
be 16bit instead of 12bit

No speed diff observed.

Note that the NEON implementation was using 32bit calc already.

Change-Id: If06935db5c56a77fc9cefcb2dec617483f5f62b4
introduce a special quantization function for WHT

WHT is somewhat a special case: no sharpen[] bias, etc.
Will be useful in a later CL when precision of input is changed.

Change-Id: I851b06deb94abdfc1ef00acafb8aa731801b4299
gif2webp: Disable output of ICC profile by default

This is to discourage generation of animated WebP images with ICC
profile, as
the real-world use-case for such images is rare at best.

Output of ICC/XMP metadata is now controlled by the '-metadata' option.

Change-Id: I8e3e29878c32bf46cbc661f50661bac602603c43
gif2webp: Backward compatibility for giflib version <= 4.1.3

Fixes https://code.google.com/p/webp/issues/detail?id=172

We use 'int' instead of 'GifWord', which was introduced in version
4.1.4.

Tested OK on 4.1.3
(http://sourceforge.net/projects/giflib/files/giflib-4.x/giflib%204.1.3/)
and 5.0.4

Change-Id: I77628b0f9175a91eb3a22e64fc55dd00633add1f
Merge "cwebp: print metadata stats when no output file is given"
dwebp.1: fix typo

ICM4 -> IMC4

Change-Id: I065a1ac0dfd0b60efa782bc1a4df1adcb28b90e4
drop: ifdef __cplusplus checks from C files

the prototypes are already marked in the headers

Change-Id: I172fe742200c939ca32a70a2299809b8baf9b094
Merge "autoconf: add --disable-wic"
add some checks on error paths

malloc failure could lead to free'ing non-initialized pointers

Change-Id: I8156aac1fce9a47825cfd0d88eb2bd8c38a630d5
dwebp: let -- stop parameter parsing

this enables dwebp to accept input files starting with '-'

Change-Id: I1e2c9c7bc2963d77be039c99e72f744560f0b0a2
cwebp: let -- stop parameter parsing

this enables cwebp to accept input files starting with '-'

Change-Id: I13b506886c3df8a4e8fb350f3d365eaf7e072a4a
vwebp: let -- stop parameter parsing

this enables vwebp to accept input files starting with '-'

Change-Id: I8467bb719ba745b2aa14a5c5ce2ff392cd9601d5
gif2webp: let -- stop parameter parsing

this enables gif2webp to accept input files starting with '-'

Change-Id: I994a5587e16e3af83ca45bfda8caf2dc39068b6c
Merge changes I994a5587,I8467bb71,I13b50688,I1e2c9c7b

* changes:
  gif2webp: let -- stop parameter parsing
  vwebp: let -- stop parameter parsing
  cwebp: let -- stop parameter parsing
  dwebp: let -- stop parameter parsing
Merge "drop: ifdef __cplusplus checks from C files"
simplify __cplusplus ifdef

drop c_plusplus which is from a quite ancient pre-standard compiler

Change-Id: I9e357b3292a6b52b14c2641ba11f4f872c04b7fb
fix bug in TrellisQuantize

the *quantized* level should be clipped to 2047, not the
original coeff.
(similar problem was fixed in the regular quantize function
quite some time ago)

Change-Id: I2fd2f8d94561ff0204e60535321ab41a565e8f85