bug#17993: 24.4.50; doc string of `hi-lock-file-patterns-prefix'

[Drew Adams]

Doc string:

  Search target for finding hi-lock patterns at top of file.

This is a variable.  The description is confusing/unclear, because
"Search" is too easily parsed as a verb (as opposed to parsing "Search
target" as a noun phrase: the target of a search).

And explain: (a) what such a pattern is, (b) what "top of file" means,
and (c) what search is involved.



In GNU Emacs 24.4.50.1 (i686-pc-mingw32)
 of 2014-06-28 on ODIEONE
Bzr revision: 117431 rgm@gnu.org-20140628015517-eku6hj8mpgcvfnso
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/snapshot/trunk
 --enable-checking=yes,glyphs 'CFLAGS=-O0 -g3'
 LDFLAGS=-Lc:/Devel/emacs/lib 'CPPFLAGS=-DGC_MCHECK=1
 -Ic:/Devel/emacs/include''