caches: extract some config reading in 'shouldwarmcache'

caches: pass the transaction to the "shouldwarncache" logic This will allow to have smarter mode about cache warming (eg: only warm them for server transaction.

caches: record 'desc' attribute on transaction This is useful to know if a transaction if server side or not.

caches: protect against missing connection If the connection cannot be established, we should not try to use it.

evolve: don't show working directory obsolete message if we were on it This patch tweaks showing wc obsolete message functionality to not show the message if the operation led us to the same changeset we were on before and it didn't obsoleted it. This make failed updates, update on current changeset and a pull with no change omit showing the message. This has some cons like if you are on rev 1 which is obsolete and you do `hg up <revset>` where revset is some revset which resolves to the rev 1, we won't show the warning as shown earlier.

prev: jump to parent's successor if parent is obsolete and topic is involved `hg stack` shows a linear chain of commits even when they are not linear chain and some changesets are obsoleted and have successors as separate head. This is very nice to have a post evolution view of the stack. However when `hg prev` is run on an unstable changeset whose parent is obsolete and does not topic but parents successor has the topic, it shows no parent on the topic. This patch makes `hg prev` update to parent's successor and make things follow the stack order.

tests: add a test showing wrong behaviour doing `hg prev` on orphan cset If there is an unstable changeset in the topic stack, whose parent is not a part of stack but has a successor which is part of stack, hg stack does shows them in linear order, but `hg prev` on that orphan changset says no parent on that topic. However it should update to the successor of the changeset. It will be fixed in the next patch.

test: update output to 02fdb8c018aa Now that we have directaccess in core, we get a new warning message when updating to a hidden changeset. Update the tests. CORE-TEST-OUTPUT-UPDATE: 02fdb8c018aa

test: update output to 9b3f95d9783d The unstable graph nodes are now shown with the character "*", update the test outputs. CORE-TEST-OUTPUT-UPDATE: 9b3f95d9783d

stablesort: use parent filtering in a place we forgot to Freak merge striked again.

obshashrange: add a progressbar to upgrade This section is the slowest, have some progress idea would be useful.

stablerange: add an sql index on subranges id too This should speed up query that find super ranges.

obshashrange: less brutal reset when receiving markers on existing node We now target the affected ranges only. The implementation is still slow but that should be better than what we had before.

obshashrange: update the cache updating logic Use the more modern option when available. (Same as the other caches).