added database module and tests
improved database module

* moved creation of directory structure to new-method
* wrote some plain old documentation
* improved and added appropriate tests
improved store-method: checking for valid hash-reference
added list-method
made store-routine more robust (checking args)
moved suppression of STDERR to subroutine
added test for undef hash-reference
improved store routine

* blessed hash-references are converted to unblessed now
* adjusted documentation
* added appropriate tests
corrected copyright to Innercircle
refactored user module by using database module

* introduced new (class/instance) methods
* made some interface changes
* added tests for user module
adjusted modules according to changes in user module

* restructured app module (BeerPlusPlus) and adjusted welcome template
* cleaned up code in login module
* adjusted statistics plugin and its appropriate template
adjusted ignore-list
wrote documentation for user module
adjusted ignore-list
added test module

* added module for testing modules which use the database module
* adjusted the user module test
improved database test module

* moved setting of datadir to separate subroutine so it can be
  called/reset several times during the test
* added POD regarding the author and licence
added test utility module
adjusted database test by using test modules
added version number
improved description