Documentation: spell 'git cmd' without dash throughout

The documentation was quite inconsistent when spelling 'git cmd' if it
only refers to the program, not to some specific invocation syntax:
both 'git-cmd' and 'git cmd' spellings exist.

The current trend goes towards dashless forms, and there is precedent
in 647ac70 (git-svn.txt: stop using dash-form of commands.,
2009-07-07) to actively eliminate the dashed variants.

Replace 'git-cmd' with 'git cmd' throughout, except where git-shell,
git-cvsserver, git-upload-pack, git-receive-pack, and
git-upload-archive are concerned, because those really live in the
$PATH.
diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
index 52c0538..0412b48 100644
--- a/Documentation/git-push.txt
+++ b/Documentation/git-push.txt
@@ -112,7 +112,7 @@
 
 --repo=<repository>::
 	This option is only relevant if no <repository> argument is
-	passed in the invocation. In this case, 'git-push' derives the
+	passed in the invocation. In this case, 'git push' derives the
 	remote name from the current branch: If it tracks a remote
 	branch, then that remote repository is pushed to. Otherwise,
 	the name "origin" is used. For this latter case, this option
@@ -126,11 +126,11 @@
 +
 is that #1 always pushes to "public" whereas #2 pushes to "public"
 only if the current branch does not track a remote branch. This is
-useful if you write an alias or script around 'git-push'.
+useful if you write an alias or script around 'git push'.
 
 --thin::
 --no-thin::
-	These options are passed to 'git-send-pack'.  Thin
+	These options are passed to 'git send-pack'.  Thin
 	transfer spends extra cycles to minimize the number of
 	objects to be sent and meant to be used on slower connection.