convert: option to set date and time for svn commits
Converting to subversion repository is not preserving original commit dates as
it may break some subversion functionality if commit dates are not monotonically
increasing.
This patch adds `convert.svn.dangerous-set-commit-dates` configuration option
to change this behaviour and enable commit dates convertion for those who want
to take risks.
Subversion always uses commit dates with UTC timezone, so only timestamps
are used.
Test `test-convert-svn-sink.t` uses `svnxml.py` script to dump history of svn
repositories. Atm the script is not printing `date` field from svn log. This
patch changes this to allow checks on correctness of date and time convertion.
Documentation is updated. Additional test case is added to test commit dates
convertion.
Differential Revision: https://phab.mercurial-scm.org/D9721
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).