pjsip: restart video port if changing format converter fails

Ignore-this: e9e8b9b7470bed90e6bc69e0aaeae9c4

darcs-hash:20140821143848-56b4d-638e9b0b6e7870db2c8afc1c12a92b9e21447157
pjsip: use the supplied fps values, don't multiply them by 3/2

Ignore-this: 15152a5583135ddcc95d01f2bad4d09

darcs-hash:20140825085049-56b4d-47f6c40ada6964c86a7890be568c434adf844cb5
pjsip: fix registering converter factories

Ignore-this: ad3276dda6b9a0a86bd0b0c54bf55aa

The list needs to be ordered from highest to lowest priority, not the other way around.

darcs-hash:20140827104246-56b4d-bcc92d1166c54cdf0e519d9be7a65b809398c7e4