Merge pull request #33 from tidwall/dev1.3

Update build tools and add Arch info to startup message

1.2

Fix gcc compile warning

Link commands to docs site

Fix compare and swap mismatch

Fixes #15

Fix lto out of bounds false positive

The GCC compiler link-time optimizern was seeing an index as out
of bounds, even though it couldn't possible be. The fix was to
change the type from 'int' to 'size_t', which makes more sense
anyhow.

Fixes #10

Merge pull request #3 from tidwall/tests

Merge tests