- fix handling of pointcache dependencies on slave (correct repathing) and on client (bad frame dependency range)
- add Force Upload option on master to force dependencies upload and download (don't reuse local copies outside of slave cache)
- add links back to main page on job web page
- client limit dependencies to rendered frame range (it used to add all point cache frames)

Thanks to Philippe Van Hecke for raising the issue by email.

[#29648] patch for netrender: correctly send smoke cache domain

Both by Philippe Van Hecke

Render engine support was expended to be able to specify non-builtin engines.

- remove/comment unused variables
- remove unused imports
- fixed some bugs using incorrect variables

Add rna callback to server address property so that it correctly checks if the server exists when the value changes.