Update English in-game weapon/utility descriptions

Branch name:
weapondescupdate

You can find this branch on
https://bitbucket.org/Wuzzy2/hedgewars-wuzzy

You can view the diff of the (only (so far)) commit here:
https://bitbucket.org/Wuzzy2/hedgewars-wuzzy/commits/05a4548fb6a0c2526182e57f067
4320189092818

Purpose of code changes on this branch:
Update the English description strings for weapons and utilities to be more 
helpful, especially show more controls for the weapons and utilities.

Notably, I also added an description for the air mine.

Also this fixes a bunch of typos, no more camel case, and some factual mistakes 
are also corrected. And lastly, I made the line breaks so they are (hopefully) 
more pleasant to read.

When reviewing my code changes, please focus on:
Whether you think the new descriptions are actually more helpful.

I have tested all descriptions in-game and made sure the line breaks are not at 
awkward positions.

Original issue reported on code.google.com by almikes@aol.com on 9 Aug 2015 at 2:15

RobWatlingSF / hedgewars

Update English in-game weapon/utility descriptions #979