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