Support for slashes in path to simulation

[cphyc]

Steps to reproduce

Add a simulation with a path containing slashes. The internal links used by the webserver incorrectly strips them away or do so inconsistently. This results in broken link on the web interface and plots do not show up.

Temporary work around

This can be fixed temporarily by changing the path to the simulation to another one without slashes (assuming the path exists).

sqlite3 database.db
> update "simulations" set basename="NEW_PATH_WITHOUT_SLASHES" where basename="OLD_PATH/WITH/SLASHES";