bundle2: add an unbundle part responsible from unbundling part We have a new unbundle class and it is now responsible from extracting its own data. The top level bundler only extracts the header (to detect an end of stream marker) then leaves everything else to the `unbundlepart` class. The ultimate goal is to have `unbundlepart` responsible for lazily extracting its payload. This is mostly code movement.

bundle2: extract stream/unpack logic in an unpackermixin The coming `unbundlepart` will need the same kind of method than `unbundle20` for unpacking data from the stream. We extract them into a mixin class before the creation of `unbundlepart`.

exchange: restore truncated comment The old version of this comment appeared to have been trunca

grep: highlight all matched words "hg grep" highlights first matched word only. This behavior is different from GNU grep. This patch makes highlight all matched words.

phase: add a passing test for (issue3575) Apparently this issue was fixed along the way (If it ever existed at all…)

run-tests: allow test paths in other directories Previously, test paths were assumed to be in the same directory and wouldn't have a directory component. If a path with a directory component was specified, it would be filtered out. This change allow paths to contain directories. This in turn allows tests from other directories to be executed. Executing tests in other directories may break assumptions elsewhere in the testing code. However, on initial glance, things appear to "just work." This approach of running tests from other directories is successfully being used at https://hg.mozilla.org/hgcustom/version-control-tools/file/7085790ff3af/run-mercurial-tests.py