Documentation: quote commit messages consistently.

Documentation quotes commit messages 14 times with double-quotes, and 7
times with single-quotes. The patch turns everything to double-quotes.

A nice side effect is that documentation becomes more Windoze-friendly
as AFAIK single quotes won't work there.
Signed-off-by: NSergei Organov <osv@javad.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/core-tutorial.txt

@@ -833,7 +833,7 @@ that branch, and do some work there.
 ------------------------------------------------
 $ git checkout mybranch
 $ echo "Work, work, work" >>hello
-$ git commit -m 'Some work.' -i hello
+$ git commit -m "Some work." -i hello
 ------------------------------------------------
 
 Here, we just added another line to `hello`, and we used a shorthand for
@@ -858,7 +858,7 @@ hasn't happened in the `master` branch at all. Then do
 ------------
 $ echo "Play, play, play" >>hello
 $ echo "Lots of fun" >>example
-$ git commit -m 'Some fun.' -i hello example
+$ git commit -m "Some fun." -i hello example
 ------------
 
 since the master branch is obviously in a much better mood.
@@ -1613,8 +1613,8 @@ in both of them.  You could merge in 'diff-fix' first and then
 'commit-fix' next, like this:
 
 ------------
-$ git merge -m 'Merge fix in diff-fix' diff-fix
-$ git merge -m 'Merge fix in commit-fix' commit-fix
+$ git merge -m "Merge fix in diff-fix" diff-fix
+$ git merge -m "Merge fix in commit-fix" commit-fix
 ------------
 
 Which would result in:

Documentation/everyday.txt

@@ -109,7 +109,7 @@ $ tar zxf frotz.tar.gz
 $ cd frotz
 $ git-init
 $ git add . <1>
-$ git commit -m 'import of frotz source tree.'
+$ git commit -m "import of frotz source tree."
 $ git tag v2.43 <2>
 ------------
 +
@@ -300,7 +300,7 @@ $ git merge topic/one topic/two && git merge hold/linus <8>
 $ git checkout maint
 $ git cherry-pick master~4 <9>
 $ compile/test
-$ git tag -s -m 'GIT 0.99.9x' v0.99.9x <10>
+$ git tag -s -m "GIT 0.99.9x" v0.99.9x <10>
 $ git fetch ko && git show-branch master maint 'tags/ko-*' <11>
 $ git push ko <12>
 $ git push ko v0.99.9x <13>

Documentation/git-reset.txt

@@ -157,7 +157,7 @@ need to get to the other branch for a quick bugfix.
 ------------
 $ git checkout feature ;# you were working in "feature" branch and
 $ work work work       ;# got interrupted
-$ git commit -a -m 'snapshot WIP'                 <1>
+$ git commit -a -m "snapshot WIP"                 <1>
 $ git checkout master
 $ fix fix fix
 $ git commit ;# commit with real log