Create a Strategy pattern interface for unicode string comparator

[Wang-Yue]

Right now Pinyin comparator is hooked into the internal implementation of the player ui. It's better to have a Strategy pattern interface for this purpose. A factory object can generate user defined comparator.

The comparators themselves can be standalone plugins that's hooked into your plugin framework.

Also it's not a good idea to have a huge pinyin table that's built into the player binary. Usually it's done by linking the plugin itself to some i18n library (such as ICU).