Make webui translateable.

[envy]

Extract all static strings and put them in a header.
Look other projects to find out how they do it.

[ascillato]

May be a good option for the library to receive the text from the main program, so the webpage title, the labels (physical address) and so on, can be sent when registering from the main program and there is no need of making new headers or files for translation.

by default, can be the actual text, but can be replaced on registering options.

What do you think?