Merge branch 'ab/i18n-scripts-basic'

* ab/i18n-scripts-basic:
  Makefile: add xgettext target for *.sh files
  git-sh-i18n.sh: add GIT_GETTEXT_POISON support
  git-sh-i18n.sh: add no-op gettext() and eval_gettext() wrappers
  git-sh-i18n--envsubst: our own envsubst(1) for eval_gettext()

Documentation/git-sh-i18n--envsubst.txt

@@ -0,0 +1,26 @@
+git-sh-i18n--envsubst(1)
+========================
+
+NAME
+----
+git-sh-i18n--envsubst - Git's own envsubst(1) for i18n fallbacks
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+plumbing scripts and/or are writing new ones.
+
+git-sh-i18n--envsubst is Git's stripped-down copy of the GNU
+`envsubst(1)` program that comes with the GNU gettext package. It's
+used internally by linkgit:git-sh-i18n[1] to interpolate the variables
+passed to the the `eval_gettext` function.
+
+No promises are made about the interface, or that this
+program won't disappear without warning in the next version
+of Git. Don't use it.
+
+GIT
+---
+Part of the linkgit:git[1] suite

Documentation/git-sh-i18n.txt

@@ -0,0 +1,42 @@
+git-sh-i18n(1)
+==============
+
+NAME
+----
+git-sh-i18n - Git's i18n setup code for shell scripts
+
+SYNOPSIS
+--------
+'. "$(git --exec-path)/git-sh-i18n"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git sh-i18n scriptlet is designed to be sourced (using
+`.`) by Git's porcelain programs implemented in shell
+script. It provides wrappers for the GNU `gettext` and
+`eval_gettext` functions accessible through the `gettext.sh`
+script, and provides pass-through fallbacks on systems
+without GNU gettext.
+
+FUNCTIONS
+---------
+
+gettext::
+	Currently a dummy fall-through function implemented as a wrapper
+	around `printf(1)`. Will be replaced by a real gettext
+	implementation in a later version.
+
+eval_gettext::
+	Currently a dummy fall-through function implemented as a wrapper
+	around `printf(1)` with variables expanded by the
+	linkgit:git-sh-i18n--envsubst[1] helper. Will be replaced by a
+	real gettext implementation in a later version.
+
+GIT
+---
+Part of the linkgit:git[1] suite