Update git(7) man-page for the C wrapper.

The program 'git' now has --exec-path which needs explaining.

Renamed old "DESCRIPTION" to "CORE GIT COMMANDS" to make room for
"OPTIONS" while following follow some sort of convention.

Also updated AUTHORS section to pat my own back a bit.

Signed-off-by: Andreas Ericsson <ae@op5.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git.txt

@@ -8,13 +8,31 @@ git - the stupid content tracker
 
 SYNOPSIS
 --------
-'git-<command>' <args>
+'git' [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ARGS]
 
 DESCRIPTION
 -----------
-
-This is reference information for the core git commands.
-
+'git' is both a program and a directory content tracker system.
+The program 'git' is just a wrapper to reach the core git programs
+(or a potty if you like, as it's not exactly porcelain but still
+brings your stuff to the plumbing).
+
+OPTIONS
+-------
+--version::
+	prints the git suite version that the 'git' program came from.
+
+--help::
+	prints the synopsis and a list of available commands.
+
+--exec-path::
+	path to wherever your core git programs are installed.
+	This can also be controlled by setting the GIT_EXEC_PATH
+	environment variable. If no path is given 'git' will print
+	the current setting and then exit.
+
+CORE GIT COMMANDS
+-----------------
 Before reading this cover to cover, you may want to take a look
 at the link:tutorial.html[tutorial] document.
 
@@ -533,9 +551,12 @@ Discussion[[Discussion]]
 ------------------------
 include::../README[]
 
-Author
-------
-Written by Linus Torvalds <torvalds@osdl.org> and the git-list <git@vger.kernel.org>.
+Authors
+-------
+	git's founding father is Linus Torvalds <torvalds@osdl.org>.
+	The current git nurse is Junio C. Hamano <junkio@cox.net>.
+	The git potty was written by Andres Ericsson <ae@op5.se>.
+	General upbringing is handled by the git-list <git@vger.kernel.org>.
 
 Documentation
 --------------