difftool: fix documentation problems

This patch makes the difftool docs always refer to the
git-difftool script using the dashed form of the name.
Only command examples use the non-dashed form now.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/difftool/git-difftool

@@ -4,7 +4,7 @@
 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
 # git-difftool-helper script.  This script exports
 # GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
-# GIT_NO_PROMPT and GIT_MERGE_TOOL for use by git-difftool-helper.
+# GIT_DIFFTOOL_NO_PROMPT and GIT_MERGE_TOOL for use by git-difftool-helper.
 # Any arguments that are unknown to this script are forwarded to 'git diff'.
 
 use strict;
@@ -18,8 +18,7 @@ my $DIR = abs_path(dirname($0));
 sub usage
 {
 	print << 'USAGE';
-
-usage: git difftool [--no-prompt] [--tool=tool] ["git diff" options]
+usage: git difftool [--tool=<tool>] [--no-prompt] ["git diff" options]
 USAGE
 	exit 1;
 }

contrib/difftool/git-difftool.txt

@@ -11,16 +11,16 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-'git difftool' is a git command that allows you to compare and edit files
+'git-difftool' is a git command that allows you to compare and edit files
 between revisions using common merge tools.  At its most basic level,
-'git difftool' does what 'git mergetool' does but its use is for non-merge
+'git-difftool' does what 'git-mergetool' does but its use is for non-merge
 situations such as when preparing commits or comparing changes against
 the index.
 
 'git difftool' is a frontend to 'git diff' and accepts the same
 arguments and options.
 
-See linkgit:git-diff[7] for the full list of supported options.
+See linkgit:git-diff[1] for the full list of supported options.
 
 OPTIONS
 -------
@@ -30,7 +30,7 @@ OPTIONS
 	Valid merge tools are:
 	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge, and opendiff
 +
-If a merge resolution program is not specified, 'git difftool'
+If a merge resolution program is not specified, 'git-difftool'
 will use the configuration variable `merge.tool`.  If the
 configuration variable `merge.tool` is not set, 'git difftool'
 will pick a suitable default.
@@ -38,15 +38,15 @@ will pick a suitable default.
 You can explicitly provide a full path to the tool by setting the
 configuration variable `mergetool.<tool>.path`. For example, you
 can configure the absolute path to kdiff3 by setting
-`mergetool.kdiff3.path`. Otherwise, 'git difftool' assumes the
+`mergetool.kdiff3.path`. Otherwise, 'git-difftool' assumes the
 tool is available in PATH.
 +
 Instead of running one of the known merge tool programs,
-'git difftool' can be customized to run an alternative program
+'git-difftool' can be customized to run an alternative program
 by specifying the command line to invoke in a configuration
 variable `mergetool.<tool>.cmd`.
 +
-When 'git difftool' is invoked with this tool (either through the
+When 'git-difftool' is invoked with this tool (either through the
 `-t` or `--tool` option or the `merge.tool` configuration variable)
 the configured command line will be invoked with the following
 variables available: `$LOCAL` is set to the name of the temporary
@@ -56,7 +56,7 @@ of the diff post-image.  `$BASE` is provided for compatibility
 with custom merge tool commands and has the same value as `$LOCAL`.
 
 --no-prompt::
-	Do not prompt before launching a merge tool.
+	Do not prompt before launching a diff tool.
 
 CONFIG VARIABLES
 ----------------
@@ -81,13 +81,13 @@ See the `--tool=<tool>` option above for more details.
 
 SEE ALSO
 --------
-linkgit:git-diff[7]::
+linkgit:git-diff[1]::
 	 Show changes between commits, commit and working tree, etc
 
 linkgit:git-mergetool[1]::
 	Run merge conflict resolution tools to resolve merge conflicts
 
-linkgit:git-config[7]::
+linkgit:git-config[1]::
 	 Get and set repository or global options