remotenames: add functionality to hoist remotebookmarks This patch adds the functionality to hoist remotebookmarks to the top level namespace. The peer of which bookmarks should be hoisted can be set using `remotenames.hoistedpeer` config option. Only bookmarks can be hoisted. If a hoisted name and local bookmark exists of the same name, the local bookmark takes precedence. While I was here, I documented the default values of two other remotenames config options. Differential Revision: https://phab.mercurial-scm.org/D2807