hgweb: show instabilities of a commit In paper, coal, gitweb and monoblue a new "tag" (or multiple, if there are many instabilities) is added to the same line that has phase, branch, etc of a changeset; in gitweb and monoblue this element has a light red background, in paper and coal the element is black and underlined. In spartan theme instabilities are shown on a separate line. While test-obsolete.t uses first(phasedivergent()) revset to pick a changeset to test, that particular changeset is also an orphan, so two different instability tags are displayed.

context: add instabilities() method to basefilectx This method is now used in webutils.commonentry(), which adds common data items (commit hash, author, date, etc) for rendering changesets in hgweb. Usually, commonentry() is given a changectx as ctx; but in views related to files (e.g. file view, diff, annotate) it's replaced by a filectx, so the latter also needs to have instabilities() method.

run-test: drop 'execfile' usage for 'common-pattern.py' file This is required for Python 3.

run-test: use byte for 'common-pattern.py' path This is required for Python 3.

templates: reword 'back to filelog' link anchor text This anchor text is problematic in two ways: first, the "back to" part assumes that you got to the page showing it via the filelog. This is not necessarily true, as there are other ways to get to that view besides the filelog view, such as for example following the history of lines from a file. Second, it uses "filelog" jargon, which refers to how each file has its own revlog. This is internal jargon that has no business being exposed to the end user. I just reworded this template to improve understanding.

hgweb: show obsolescence status of a commit As with phases, spartan theme shows a simple "obsolete: yes" on its own line (this allows replacing "yes" with something more useful in future, like output of obsfate* template functions). Everywhere else a new "tag" is added to the same line that has phase, branch, etc of a changeset; in gitweb and monoblue the element has gray background, in paper and coal the element is gray with a dashed underline.

context: add obsolete() method to basefilectx This method is now used in webutils.commonentry(), which adds common data items (commit hash, author, date, etc) for rendering changesets in hgweb. Usually, commonentry() is given a changectx as ctx; but in views related to files (e.g. file view, diff, annotate) it's replaced by a filectx, so the latter also needs to have obsolete() method.