Add autoreconf warnings. Replace obsolete AC_TRY_COMPILE.
Remove redundant checks (already done by LT_INIT).
Remove INCLUDES. Obsolete, appears unused anyway.
Use same build template as bitcoin. Add bitcoin_secp.m4.
Branch-free point addition
Rearrange _gej_add_ge to save an _fe_negate
Merge pull request #98

fb1bb0b Rearrange _gej_add_ge to save an _fe_negate (Peter Dettman)
9338dbf Branch-free point addition (Pieter Wuille)
Document some preconditions
Merge pull request #99

c27fdc0 Document some preconditions (Pieter Wuille)
Merge pull request #96

6fac238 Use same build template as bitcoin. Add bitcoin_secp.m4. (kiwigb)
f9aac5b Remove INCLUDES. Obsolete, appears unused anyway. (kiwigb)
db72c18 Add autoreconf warnings. Replace obsolete AC_TRY_COMPILE. Remove redundant checks (already done by LT_INIT). (kiwigb)
Add non-null and unused-result warnings for the external API.

GCC (and clang) supports extensions to annotate functions so that their
 results must be used and so that their arguments can't be statically
 provable to be null. If a caller violates these requirements they
 get a warning, so this helps them write correct code.

I deployed this in libopus a couple years ago with good success, and
 the implementation here is basically copied straight from that.

One consideration is that the non-null annotation teaches the optimizer
 and will actually compile out runtime non-nullness checks as dead-code.
 Since this is usually not whats wanted, the non-null annotations are
 disabled when compiling the library itself.

The commit also removes some dead inclusions of assert.h and introduces
 compatibility macros for restrict and inline in preparation for some
 portability improvements.
Merge pull request #101

8563713 Add non-null and unused-result warnings for the external API. (Gregory Maxwell)
Merge branch 'master' of https://github.com/bitcoin/secp256k1 into coz-arithmetic