Fix 'timescales' -> 'time scales', and other assorted typos

Fix 'timescales' -> 'time scales', and other assorted typos

As pointed out by Granddaddy:
* "because it takes a quite a bit": The first "a" is redundant
* "timescales": this is awkward: "time-scales" is more logical than
  "timescales."  I suggest you hyphenate this word.
* "unfolding experiment, they observed ...": "the" is a typo

I went with "time scale" which we see in abstracts for evans97, lu99,
evans01, msli06, mickler07.  "timescale" shows up in dietz04, but I
agree with Graddaddy that it's awkward.  I imagine the shortening
comes from writing too much software and/or speaking German ;).

I fixed some other things I noticed along the way.