cmdutil: create dirs for templated cat file output Previously, the caller was responsible for creating the directory structure of files written out using a path template. This is onerous, especially if the exact filenames are not known upfront, but are being accessed via a matcher. This patch changes things so that hg will attempt to create the appropriate directories before writing the output file. Differential Revision: https://phab.mercurial-scm.org/D1332