Commits

Wes McKinney authored a94c03a02f1
ARROW-809: [C++] Do not write excess bytes in IPC writer after slicing arrays cc @itaiin Author: Wes McKinney <wes.mckinney@twosigma.com> Closes #555 from wesm/ARROW-809 and squashes the following commits: 318c748 [Wes McKinney] Fix compiler warning 7fd6410 [Wes McKinney] Add sparse union test 290a300 [Wes McKinney] clang-format 1d14aa8 [Wes McKinney] Buffer truncation for unions 51f450f [Wes McKinney] Fix struct 7da5cac [Wes McKinney] Add List test and fix implementation. Fix list comparison bug for sliced arrays 9da3936 [Wes McKinney] Refactor to construct explicit non-nullable arrays 33eaa53 [Wes McKinney] Sliced array buffer truncation for fixed size types, string/binary