new: fix hgignore for real
new: fix hgignore for real

There was an attempt to fix hgignore in #4158, but unfortunately the fix
was incorrect -- hgignore glob syntax is not in fact identical to
gitignore syntax.

To get rooted ignores in Mercurial we must use the regex-based syntax,
so we have no choice but to define a separate set of ignores.

nipunn1313/cargo,rust-lang/cargo,nipunn1313/cargo,tshepang/cargo,tshepang/cargo,vojtechkral/cargo,achanda/cargo,rust-lang/cargo,eminence/cargo,eminence/cargo,rustyhorde/cargo,eminence/cargo,rustyhorde/cargo,nipunn1313/cargo,eminence/cargo,achanda/cargo,rust-lang/cargo,nipunn1313/cargo,achanda/cargo,tsurai/cargo,achanda/cargo,rustyhorde/cargo,tsurai/cargo,rustyhorde/cargo,vojtechkral/cargo,tsurai/cargo,vojtechkral/cargo,vojtechkral/cargo,tsurai/cargo,rust-lang/cargo,tsurai/cargo,tshepang/cargo,tshepang/cargo