Interface for sdcv (StartDict console version).

Translate word by sdcv (console version of Stardict), and display
translation use popup tooltip or buffer.

Below are commands you can use:

`sdcv-search-pointer'
Search around word and display with buffer.
`sdcv-search-pointer+'
Search around word and display with `popup tooltip'.
`sdcv-search-input'
Search input word and display with buffer.
`sdcv-search-input+'
Search input word and display with `popup tooltip'.

Tips:

If current mark is active, sdcv commands will translate
region string, otherwise translate word around point.