jquery.timeselector.js: FIX: option handling

# What: Picking directly arguments[i] (no error if not exists), merging it with defaults, attaching defaults
# Why: Setting options as documented (see https://github.com/nicolaszhao/timeselector#options) made timeselector not work at all, unfortunately without an javascript error or something else
# Note: I fear I didn't fully understand the original code at that place ... beg your pardon if mine's is rather primitive, but it works ...