implement type and sex attribute addition to new definitions
replace search window's definitionBox with meaningBox
add edit buttons to meaining form

ui interaction is ok but functionality is not implemented yet
fix #54 close #21 close #22"

* 54: Add/remove meaning is buggy when adding word
* 21: Add 'type' attribute to definitions
* 22: Add 'sex' attribute to words
- several code enhancements
fix duplicate meaning name in NewDefinitionWindow