test: prepare tests for removing date aliases In the next patch, I'm gonna removing the global command aliases that force the epoch date but some tests either fail or their output change after that. Instead I'm copying the needed aliases in the test files that will otherwise change. Update test-rebase-obsolete.t because a revision hash is based on the epoch date after a 'commit --amend' and the output will change after removing date aliases. Update test-subrepo-git.t as the git subrepo doesn't use traditional date mechanisms. I'm not sure that updating the git subrepo to support default-date make sense. Add the commit alias to the test in order for making it pass after removing the date aliases globally.

devel: update blackbox to use default-date Blackbox now obeys the 'devel.default-date' option. As a side effect we can delete the mock for blackblox related tests.

devel: use default-date config field when creating obsmarkers Also use the default-date when creating obsmarkers. Currently they are created with the current date and without any option to force their value. To test the feature, we remove some of the many 'glob' used to match obsmarker date in the tests.

devel: activate default-date in tests It will make writing future tests more easier for everyone as we won't need to glob dates anymore in tests.

devel: add a config field to force dates to timestamp 0 Add a new config field named default-date under the devel section to force all implicits date to a specific value. If a explicit date is passed, it will override the default. This patch only affect changesets. Other usages (blackbox, obsmarkers) are updated in later patchs. The test runner is setting a bunch of alias to force the '--date' argument. We will replace theses aliases in a later patch.

ui: add the possiblity to get a date config field Add the method configdate to read a date from configuration. It uses the util.rawparsedate refactored earlier to support all standard date formats.