manpages: italicize command names

This includes nongit commands like RCS 'merge'.  This patch only
italicizes names of commands if they had no formatting before.

Signed-off-by: Jonathan Nieder <jrnieder@uchicago.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -568,7 +568,7 @@ diff.external::
 
 diff.renameLimit::
 	The number of files to consider when performing the copy/rename
-	detection; equivalent to the git-diff option '-l'.
+	detection; equivalent to the 'git-diff' option '-l'.
 
 diff.renames::
 	Tells git to detect renames.  If set to any boolean value, it
@@ -844,7 +844,7 @@ instaweb.port::
 
 log.date::
 	Set default date-time mode for the log command. Setting log.date
-	value is similar to using git-log's --date option. The value is one of the
+	value is similar to using 'git-log'\'s --date option. The value is one of the
 	following alternatives: {relative,local,default,iso,rfc,short}.
 	See linkgit:git-log[1].
 

Documentation/git-apply.txt

@@ -18,7 +18,7 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Reads supplied diff output and applies it on a git index file
+Reads supplied 'diff' output and applies it on a git index file
 and a work tree.
 
 OPTIONS
@@ -165,9 +165,9 @@ behavior:
 * `error-all` is similar to `error` but shows all errors.
 
 --inaccurate-eof::
-	Under certain circumstances, some versions of diff do not correctly
+	Under certain circumstances, some versions of 'diff' do not correctly
 	detect a missing new-line at the end of the file. As a result, patches
-	created by such diff programs do not record incomplete lines
+	created by such 'diff' programs do not record incomplete lines
 	correctly. This option adds support for applying such patches by
 	working around this bug.
 

Documentation/git-merge-file.txt

@@ -85,7 +85,7 @@ Written by Johannes Schindelin <johannes.schindelin@gmx.de>
 Documentation
 --------------
 Documentation by Johannes Schindelin and the git-list <git@vger.kernel.org>,
-with parts copied from the original documentation of RCS merge.
+with parts copied from the original documentation of RCS 'merge'.
 
 GIT
 ---

Documentation/git-merge-index.txt

@@ -41,7 +41,7 @@ processes them in turn only stopping if merge returns a non-zero exit
 code.
 
 Typically this is run with a script calling git's imitation of
-the merge command from the RCS package.
+the 'merge' command from the RCS package.
 
 A sample script called `git-merge-one-file` is included in the
 distribution.

Documentation/git-rerere.txt

@@ -7,7 +7,7 @@ git-rerere - Reuse recorded resolution of conflicted merges
 
 SYNOPSIS
 --------
-'git rerere' [clear|diff|status|gc]
+'git rerere' ['clear'|'diff'|'status'|'gc']
 
 DESCRIPTION
 -----------
@@ -49,7 +49,7 @@ conflicts.  Additional arguments are passed directly to the system
 
 'status'::
 
-Like diff, but this only prints the filenames that will be tracked
+Like 'diff', but this only prints the filenames that will be tracked
 for resolutions.
 
 'gc'::

Documentation/gitdiffcore.txt

@@ -7,7 +7,7 @@ gitdiffcore - Tweaking diff output (June 2005)
 
 SYNOPSIS
 --------
-git diff *
+'git diff' *
 
 DESCRIPTION
 -----------
@@ -16,7 +16,7 @@ The diff commands `git-diff-index`, `git-diff-files`, and `git-diff-tree`
 can be told to manipulate differences they find in
 unconventional ways before showing `diff` output.  The manipulation
 is collectively called "diffcore transformation".  This short note
-describes what they are and how to use them to produce diff output
+describes what they are and how to use them to produce 'diff' output
 that is easier to understand than the conventional kind.