generic_helper.rb: removed trailing whitespace.
configuration_helper.rb: fixed warning related to deprecated usage of parseconfig library.
lpim.rb, list command: the day can now be specified.
GenericHelper#decode_date: added support for day in the current week, and the format 'YYYY-MM-DD'.
lpim.rb: Fixed event timestamps handling.

Event timestamps were not correctly interpreted, especially the 'floating' concept was ignored.