b0210a9 Merge pull request #135
ee3eb4b Fix a memory leak and add a number of small tests.
4d879a3 Merge pull request #134
d5e8362 Merge pull request #127
7b92cf6 Merge pull request #132
0bf70a5 Merge pull request #133
29ae131 Make scalar_add_bit test's overflow detection exact
9048def Avoid undefined shift behaviour
efb7d4b Use constant-time conditional moves instead of byte slicing
d220062 Merge pull request #131
82f9254 Fix typo
601ca04 Merge pull request #129
35399e0 Bugfix: b is restricted, not r
c35ff1e Convert lambda splitter to pure scalar code.
cc604e9 Avoid division when decomposing scalars
ff8746d Add secp256k1_scalar_mul_shift_var
bd313f7 Merge pull request #119
276f987 Merge pull request #124
25d125e Merge pull request #126
24b3c65 Add a test case for ECDSA recomputing infinity
32600e5 Add a test for r >= order signature handling
4d4eeea Make secp256k1_fe_mul_inner use the r != property
be82e92 Require that r and b are different for field multiplication.
597128d Make num optional
659b554 Make constant initializers independent from num
0af5b47 Merge pull request #120
e2e8a36 Merge pull request #117
c76be9e Remove unused num functions
4285a98 Move lambda-splitting code to scalar.
f24041d Switch all EC/ECDSA logic from num to scalar
6794be6 Add scalar splitting functions
d1502eb Add secp256k1_scalar_inverse_var which delegates to GMP
b5c9ee7 Make test_point_times_order test meaningful again
0b73059 Switch wnaf splitting from num-based to scalar-based
1e6c77c Generalize secp256k1_scalar_get_bits
5213207 Add secp256k1_scalar_add_bit
3c0ae43 Merge pull request #122
6e05287 Do signature recovery/verification with 4 possible recid case
e3d692f Explain why no y=0 check is necessary for doubling
f7dc1c6 Optimize doubling: secp256k1 has no y=0 point
666d3b5 Merge pull request #121
2a54f9b Correct typo in comment
9d64145 Merge pull request #114
99f0728 Fix secp256k1_num_set_bin handling of 0
d907ebc Add bounds checking to field element setters
bb2cd94 Merge pull request #116
665775b Don't split the g factor when not using endomorphism
9431d6b Merge pull request #115
e2274c5 build: osx: attempt to work with homebrew keg-only packages

git-subtree-dir: src/secp256k1
git-subtree-split: b0210a95da433e048a11d298efbcc14eb423c95f

git-subtree-dir: src/secp256k1
git-subtree-split: ad2028f9890ca40bdd32055aa0fe5c1c9af0e485

This is a long chain of errors, and there are likely other changes that could
be made to cope in other places along that chain.

If depends don't build successfully, don't bother trying again for the sake of
better logging. That's likely to hurt more than help. In this case, qt build
failed, and on the second attempt, it appeared to be successful. However, due
to a bad object from an internal gcc error on the first build, the resulting
lib was unusable. This caused bitcoin-qt to not be built, and tests and
packaging which expected bitcoin-qt to be there failed.

The root cause:
Mingw is especially crashy when using -jX, likely compounded by low-memory
environments. I've seen multiple problems with this combo in Gitian as well.

In this case:
i686-w64-mingw32-g++: internal compiler error: Killed (program cc1plus)
...
make[3]: *** [.obj/release/qdrawhelper.o] Error 4

The workaround:
Bump Travis down to using -j2 by default. Additionaly, enable --with-gui for
the windows builds. This will cause configure to fail if qt is not working
while also testing the config flag.

Other failures which may be worth revisiting separately:
- If a depends package fails, maybe remove the workdir so that it doesn't taint
  subsequent runs
- See if there's anything repeatable about the ICE when building qt

This reverts commit 7e3821c0.

For the all-off build, enable the wallet and debug. This ensures that debug
options will catch wallet problems as well.

In order to make sure the no-wallet path is still tested, disable the wallet
in the other x86_64 build.