Update git-init-db(1) and documentation of core.sharedRepository

Combine option descriptions in git-init-db(1). Reflect the changes to
additionally allow all users to read the created git repository.

Signed-off-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/config.txt

@@ -83,9 +83,12 @@ core.repositoryFormatVersion::
 	version.
 
 core.sharedRepository::
-	If true, the repository is made shareable between several users
-	in a group (making sure all the files and objects are group-writable).
-	See gitlink:git-init-db[1]. False by default.
+	When 'group' (or 'true'), the repository is made shareable between
+	several users in a group (making sure all the files and objects are
+	group-writable). When 'all' (or 'world' or 'everybody'), the
+	repository will be readable by all users, additionally to being
+	group-shareable. When 'umask' (or 'false'), git will use permissions
+	reported by umask(2). See gitlink:git-init-db[1]. False by default.
 
 core.warnAmbiguousRefs::
 	If true, git will warn you if the ref name you passed it is ambiguous

Documentation/git-init-db.txt

@@ -8,17 +8,47 @@ git-init-db - Creates an empty git repository
 
 SYNOPSIS
 --------
-'git-init-db' [--template=<template_directory>] [--shared]
+'git-init-db' [--template=<template_directory>] [--shared[=<permissions>]]
 
 
 OPTIONS
 -------
+
+--
+
 --template=<template_directory>::
-	Provide the directory from which templates will be used.
-	The default template directory is `/usr/share/git-core/templates`.
 
---shared::
-	Specify that the git repository is to be shared amongst several users.
+Provide the directory from which templates will be used.  The default template
+directory is `/usr/share/git-core/templates`.
+
+When specified, `<template_directory>` is used as the source of the template
+files rather than the default.  The template files include some directory
+structure, some suggested "exclude patterns", and copies of non-executing
+"hook" files.  The suggested patterns and hook files are all modifiable and
+extensible.
+
+--shared[={false|true|umask|group|all|world|everybody}]::
+
+Specify that the git repository is to be shared amongst several users.  This
+allows users belonging to the same group to push into that
+repository.  When specified, the config variable "core.sharedRepository" is
+set so that files and directories under `$GIT_DIR` are created with the
+requested permissions.  When not specified, git will use permissions reported
+by umask(2).
+
+The option can have the following values, defaulting to 'group' if no value
+is given:
+
+ - 'umask' (or 'false'): Use permissions reported by umask(2). The default,
+   when `--shared` is not specified.
+
+ - 'group' (or 'true'): Make the repository group-writable, (and g+sx, since
+   the git group may be not the primary group of all users).
+
+ - 'all' (or 'world' or 'everybody'): Same as 'group', but make the repository
+   readable by all users.
+
+--
 
 
 DESCRIPTION
@@ -29,24 +59,13 @@ template files.
 An initial `HEAD` file that references the HEAD of the master branch
 is also created.
 
-If `--template=<template_directory>` is specified, `<template_directory>`
-is used as the source of the template files rather than the default.
-The template files include some directory structure, some suggested
-"exclude patterns", and copies of non-executing "hook" files.  The
-suggested patterns and hook files are all modifiable and extensible.
-
 If the `$GIT_DIR` environment variable is set then it specifies a path
 to use instead of `./.git` for the base of the repository.
 
 If the object storage directory is specified via the `$GIT_OBJECT_DIRECTORY`
 environment variable then the sha1 directories are created underneath -
 otherwise the default `$GIT_DIR/objects` directory is used.
 
-A shared repository allows users belonging to the same group to push into that
-repository. When specifying `--shared` the config variable "core.sharedRepository" 
-is set to 'true' so that directories under `$GIT_DIR` are made group writable
-(and g+sx, since the git group may be not the primary group of all users).
-
 Running `git-init-db` in an existing repository is safe. It will not overwrite
 things that are already there. The primary reason for rerunning `git-init-db`
 is to pick up newly added templates.