tigefa4u projects Trac

rework-testing branch: make it possible to run the unit-tests using the alternative database backend specified by the TRAC_TEST_DB_URI environment variable.

Decent speed is achieved by "resetting" the database instead of dropping all the tables (MySQL) or the schema (PostgreSQL). This reset operation clears all the data (`DELETE FROM` and `ALTER SEQUENCE` for PostgreSQL, `TRUNCATE TABLE` for MySQL).

As the support for alternative database backend mostly moved to `trac.test` and the `EnvironmentStub`, the code in `trac.tests.functional.FunctionalTestEnvironment` has been significantly simplified.

rework-testing branch: re-use utilities from the DB api for abstracting SQL dialect differences.

This is a first step towards running unit-tests with alternative database backends.

rework-testing branch: Makefile improvements

Make it easy to specify on the command line:
- which python version to use (`make python=<version>`), where `<version>` is one of 23, 24, 25, 26 or any other key defined in the Makefile. If no version is specified, this defaults to the python program currently in the PATH, as before.
- which db backend to use (`make db=<backend>`), where `<backend>` is one of postgres or mysql. If no backend is explicitly specified, the database backend defaults to the SQLite :memory: kind.

The setup for Python and database backends is for now placed in the Makefile itself, but I'll move that in a second step in a Makefile.cfg file.

0.12dev: port r8179, r8185 and r8186 from 0.11-stable.

0.12dev: prevent r8177 from being merged back.

During initenv, make sure the prompt questions and answers can contain unicode characters.

This will be useful for 0.12dev, when the translations are enabled and the LANG environment variable is set.

But even in 0.11.x, the input itself can contain non-ascii characters (e.g. in the project name), so first apply to 0.11-stable.

Closes #8275.

Have a more explicit ''Configuration Error'' displayed when a TracIni entry of type int (i.e. an `IntOption`) is set to a value not convertible to an int.

Closes #8264.

0.11-stable: Don't display changeset comments in browser and log for changesets where the user doesn't have view permission.

Closes #5640.

0.12dev: Don't invalidate the wiki page name cache when importing wiki pages through `trac-admin` if this doesn't create a new page.

Related to #8270.

0.12dev: Invalidate the wiki page name cache in the model, in the same transaction as the wiki page update, in the same way as the ticket field cache.

Related to #8270.