journal: report parsing errors on recover/rollback (issue4172)

rebase: do not try to reactivate deleted divergent bookmark If the currently active bookmark is divergent one, it may be resolved during rebase. Trying to activate it will raise "KeyError: 'W@diverge'".

tests: backout 00f2d29308db pid check

revset: changed spanset implementation to take hidden revisions into account Hidden revisions are now excluded from the spanset. Now this doesn't break for people using changeset evolution.

template: add 'current' to scope during {bookmarks % ...} This adds the keyword 'current' to the template scope when processing a bookmark list. The 'current' keyword resolves to the name of the currently active bookmark in the repo. This allows us to apply special labels to the current bookmark to distinguish it (especially in the case where there are multiple bookmarks on the same commit). Example: "{bookmarks % '{bookmark}{ifeq(bookmark, current, \"*\")} '}" Results in a space separated list of bookmarks where the current bookmark has an asterix.

template: add revset() template function Adds a template function that executes a revset and returns the list of revisions as the result. It has the signature 'revset(query [, args...])'. The args are optional and are applied to the query string using the standard python string.format(args) pattern. This allows things like: '{revset("parents({0})", rev)}' to produce the parents of each individual commit in the log output. If no args are specified, the revset result is cached for the duration of the templater; so it's better to not use args if performance is a concern. By itself, revset() can be used to print commit parents, print the common ancestor of a commit with the main branch, etc. It can be used with the ifcontains() function to do things like '{ifcontains(rev, revset('.'), label(...), ...)}' to color the working copy parent, to color certain branches, to color draft commits, etc.

template: add ifcontains template function Adds a template function with the signature 'ifcontains(item, set, then[, else])'. It can be used to do things like '{ifcontains('.hgignore', file_mods, label(...), ...)}' to color commits that edit the .hgignore file. A future patch will add the revset() function which will combine with ifcontains to allow us to color commits if they are in the revset.

createmarkers: allow to pass metadata for a marker only The `metadata` argument only allow to specify metadata for all new markers. We extension the format of the `relations` argument to support optional metadata argument. The first user of this should be the evolve extension who want to store parent information of pruned changeset in extra (until we make a second version of the format)