A more unique and robust solution for config sequence items

fixing issues with 2.0 commit https://github.com/s9y/Serendipity/commit/34e4341ab0fe8745ae56492227d465babe0cd387
and references https://github.com/s9y/Serendipity/commit/744a0fc32a40a260830709655c6717d7539feba8 discussion
and also adds a very nice solution for CSS only truncation with too long non-whitespaced strings :)