fsmonitor: hook up state-enter, state-leave signals Keeping the codebase in sync with upstream: Watchman 4.4 introduced an advanced settling feature that allows publishing tools to notify subscribing tools of the boundaries for important filesystem operations. https://facebook.github.io/watchman/docs/cmd/subscribe.html#advanced-settling has more information about how this feature works. This diff connects a signal that we're calling `hg.update` to the mercurial update function so that mercurial can indirectly notify tools (such as IDEs or build machinery) when it is changing the working copy. This will allow those tools to pause their normal actions as the files are changing and defer them until the end of the operation. In addition to sending the enter/leave signals for the state, we are able to publish useful metadata along the same channel. In this case we are passing the following pieces of information: 1. destination revision hash 2. An estimate of the distance between the current state and the target state 3. A success indicator. 4. Whether it is a partial update The distance is estimate may be useful to tools that wish to change their strategy after the update has complete. For example, a large update may be efficient to deal with by walking some internal state in the subscriber rather than feeding every individual file notification through its normal (small) delta mechanism. We estimate the distance by comparing the repository revision number. In some cases we cannot come up with a number so we report 0. This is ok; we're offering this for informational purposes only and don't guarantee its accuracy. The success indicator is only really meaningful when we generate the state-leave notification; it indicates the overall success of the update.

largefiles: add abstract methods in remotestore class Methods _put, _get, _stat were used in remotestore class as abstract expecting that subclass would implement them. This commit makes this fact explicit.

test-parse-date: defines explicit start/end dates for DST Prior to this patch, DST times where tested by specifying a custom TZ environment variable that didn't defined DST transition times. Due to a bug in glibc, the test fail on 32bits platforms that use timezone files generated by zic from tzcode >= 2014c (glibc >= 2.20). See https://sourceware.org/bugzilla/show_bug.cgi?id=19738 By defining explicit transition times for DST in the TZ environment variable, the test is now independant to how the system guess those transition times.

debuginstall: convert to formatter commit editor now reports its editor default template is now reported a broken vi editor (vi not in path) is still not considered a problem (!!)

largefiles: use iterbatch instead of batch This actually makes the code a little cleaner to read.

wireproto: make iterbatcher behave streamily over http(s) Unfortunately, the ssh and http implementations are slightly different due to differences in their _callstream implementations, which prevents ssh from behaving streamily. We should probably introduce a new batch command that can stream results over ssh at some point in the near future. The streamy behavior of batch over http(s) is an enormous win for remotefilelog over http: in my testing, it's saving about 40% on file fetches with a cold cache against a server on localhost.

setdiscovery: use iterbatch interface instead of batch It's a little more concise, and gives us some simple test coverage.

peer: add an iterbatcher interface This is very much like ordinary batch(), but it will let me add a mode for batch where we have pathologically large requests which are then handled streamily. This will be a significant improvement for things like remotefilelog, which may want to request thousands of entities at once.

wireproto: document quirk of _callstream between http and ssh This tripped me up when trying to use it, so it feels like we should document this to avoid future pain.

peer: raise NotImplementedError for abstract submit() method Nothing should ever call this submit method directly as it should be overridden by concrete batcher implementations.