Merge branch 'ab/test-tool-leakfix'

Plug various memory leaks in test-tool commands. * ab/test-tool-leakfix: test-tool delta: fix a memory leak test-tool ref-store: fix a memory leak test-tool bloom: fix memory leaks test-tool json-writer: fix memory leaks test-tool regex: call regfree(), fix memory leaks test-tool urlmatch-normalization: fix a memory leak test-tool {dump,scrap}-cache-tree: fix memory leaks test-tool path-utils: fix a memory leak test-tool test-hash: fix a memory leak