Some translation improvements

[costales]

- The help is not translatable
- The File -> "Open Sentences File..." string is not translatable
- "Practice Your English" should be translatable? (and it
might be better spelled as "Practice your English").
- There is a "3 _Lives" string and "3 Lives", "2 Lives" and "1 Live".
AFAIK we only need a plural form[1] (and the accelerator should be here
in each case)

[Michael Moroni (airon90)]

"Error loading the sentences. Try to load another file", "error", setup.py, Builder.py in pyenglish_lib and about dialog are non translatable too
"well done" needs only one exclamation mark.

[costales (costales)]

@Michael: One question just for my information, please. Is "Error loading the sentences. Try to load another file" appering in the app start? It must appear just when you load a new template ;)