add pool_timeout and max_connections parameters

[lcx]

Added configuration option for pool_timeout and max_connections to pass over to sequel

[bklang]

Tiny nit, but would you please add spaces after the commas?

[bklang]

Also, it occurs to me that it might be better to pass this as a hash to #establish_connection, in case we get more params in the future. The calling code would then look something like

@@connection = establish_connection connection_string(params), max_connections: max_connections, pool_timeout: pool_timeout

[bklang]

A few code nits, but thank you for your contribution!

[lcx]

Odd, no idea why I used ruby 1.8 syntax, I occasionally do that :)
Should I fix the issues or will you fix it?
Survived in production today without PoolTimeout exception with a bunch of calls to a radio station. So looks stable I would say.

[vangberg]

There are a lot of adapter specific connection options[1], so I'm wondering if it wouldn't make sense to take a connection_options configuration key, and pass verbatim to Sequel.connect?

[1] http://sequel.jeremyevans.net/rdoc/files/doc/opening_databases_rdoc.html