Some grammar and wrapping changes to scenarios/web.

Also fixed a small typo.
Some wording changes to scenarios/scrape.
Wording and line wraps for scenarios/cli.
Caps, wording, and line wrapping for scenarios/gui.

Also added a brief description for PyQt.
Wrapped and removed extra text from scenarios/db.
Wrapping, newlines, and minor wording changes to scenarios/network.
Wording, wrapping, and formatting changes for scenarios/admin.
Wrapping and wording for scenarios/ci.
Wording and wrapping for scenarios/speed.
Rewording and wrapping in scenarios/scientific.
Wording, comma and case changes (VIM->Vim) for dev/env.

Tried to normalize with no Oxford commas.
In{visible,scrutable} punctuation...
Another tiny change to intro/duction.
Quick wording changes for intro/learning.
A couple changes to dev/env.
Added back an Oxford comma in dev/env.
Removed an extra space.
Removed spaces at the ends of lines.
Merge pull request #458 from george2/grammar-and-typos

More grammar and typo fixes.
improve the description of gevent.