doc: Wordclock.doxyfile: Optimize results for C
doc: Wordclock.doxyfile: Omit full path names
doc: Wordclock.doxyfile: Enable warning for undocumented parameters
doc: Wordclock.doxyfile: Enable logfile for warnings
doc: Wordclock.doxyfile: Extract static variables
src: color.c: color_hue_waveform(): Rename argument
src: color.c: color_hue_waveform(): Fix Doxygen comment block
src: datetime: Fix Doxygen comments