[GRASS-translations] some typos

[Glynn Clements]

Maxim Dubinin wrote:

> we've just finished Russian i18n and during the process we've ran into
> several typos in English version, may be someone will be willing to fix them.

I've fixed most of the obvious typos.

I didn't touch [un]initialise[d], as I'm not sure what the policy is
regarding UK/US English spellings. We do have some other known UK
spellings (e.g. use of "grey" rather than "gray").

I didn't touch classbreak or co-ordinate, as I don't know the policy
regarding compound words.

-- 
Glynn Clements <glynn at gclements.plus.com>