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.

util: refactor util.parsedate to raises ValueError Split most of util.parsedate in util.rawparsedate and make it raises ValueError instead of error.Abort. The util.parsedate function is now just a shell function converting ValueError to error.Abort for existing users. I need to parse a date from config in a later patch and use util.rawparsedate with ui.configwith which expect a convert that raises ValueError.

match: implement __repr__() and update users (API) fsmonitor and debugignore currently access matcher fields that I would consider implementation details, namely patternspat, includepat, and excludepat. Let' instead implement __repr__() and have the few users use that instead. Marked (API) because the fields can now be None.