Add configuration parameter for database

[tcuje]

In the latest release only the roundcube database itself can be used. With the following patch any database and type, which is supported by roundcube, can be used.

[t3chguy]

Looks good, I will test this over the next few days. Thanks for sanitizing the indentation, at the time of writing Sublime Text was setup very very strangely and indentation everywhere was always bizarre.

[t3chguy]

once merged I will apply similar logic to the rewrite available in the development branch (which is somewhat faulty atm)