A new process-wide db connection pool.
A new process-wide db connection pool.

With this pool Trac will hopefully perform a lot better in setups with a large number of environments.
The default pool size is 10 connections per process, but can be changed by setting the TRAC_DB_POOL_SIZE environment variable.



git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@7190 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac