create new tracker for 'miriad'

[VincentMcIntyre]

We need a new trac set up for "miriad " as opposed to "miriad4cabb". The cabb upgrade work is a component of the overall "miriad" wiki.

[VincentMcIntyre]

The process was much as described in ​TracMigrate.

1. /local/sbin/new_trac miriad VincentMcIntyre?
2. sqlite3 /var/www/vhosts/svn.atnf.CSIRO.AU/trac/miriad4cabb/db/trac.db >/tmp/miriad4cabb.sql
3. vi /tmp/miriad4cabb.sql (change 'repository_dir' to have the uuid and path of the new repository created at step 1).
4. cat /tmp/miriad4cabb.sql | sqlite3 /tmp/miriad4cabb.db
5. cd /var/www/vhosts/svn.atnf.CSIRO.AU/trac/ sudo -u www-data mv miriad/db/trac.db miriad/db/trac.db.orig sudo -u www-data cp /tmp/miriad4cabb.db miriad/db/trac.db
6. tkdiff miriad4cabb/conf/trac.ini miriad/conf/trac.ini & sudo -u www-data cp miriad/conf/trac.ini miriad/conf/trac.ini.old sudo -u www-data vi miriad/conf/trac.ini (make sure all the old plugins have settings transferred to the new trac.ini).
7. sudo apache2ctl configtest && sudo apache2ctl graceful
8. Browse to the new site at /trac/miriad
9. Login, and try editing the front page.

Things seem to work. In some places (mainly to do with referencing plugins like azcalendar and Billing) we have had to use absolute paths. These will need to be changed as we find them.

[VincentMcIntyre]

Spent several hours looking into why there is no prefix for the "top level" of the site, e.g. trac:, which would expand to /trac/miriad in the case of this project. This is useful when dealing with plugins that don't provide prefixes for themselves, but lie outside the wiki. For example the ​TimingAndEstimationPlugin, which could be referenced from the wiki as trac:Billing, and the ​CalendarPlugin as trac:azalendar.

This feature is probably going to appear some time after trac 0.11.1, as the prefix //. The .. prefix can be used in pages at the top level of the wiki, e.g. ../azcalendar, but this is not general enough. For now, I defined a custom prefix trac: which does what I want.