emacs: Fix tramp using /bin/sh

Fixes https://github.com/termux/termux-app/issues/139

packages/emacs/build.sh

@@ -1,7 +1,7 @@
 TERMUX_PKG_HOMEPAGE=http://www.gnu.org/software/emacs/
 TERMUX_PKG_DESCRIPTION="Extensible, customizable text editor-and more"
 TERMUX_PKG_VERSION=25.0.95
-TERMUX_PKG_BUILD_REVISION=1
+TERMUX_PKG_BUILD_REVISION=2
 TERMUX_PKG_SRCURL=ftp://alpha.gnu.org/gnu/emacs/pretest/emacs-${TERMUX_PKG_VERSION}.tar.xz
 TERMUX_PKG_DEPENDS="ncurses, gnutls, libxml2"
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="--without-x --with-xpm=no --with-jpeg=no --with-png=no --with-gif=no --with-tiff=no --without-gconf --without-gsettings --with-gnutls --with-xml2"

packages/emacs/lisp-net-tramp.el.patch.beforehostbuild

@@ -0,0 +1,12 @@
+diff -u -r ../emacs-25.0.95/lisp/net/tramp.el ./lisp/net/tramp.el
+--- ../emacs-25.0.95/lisp/net/tramp.el	2016-05-17 12:16:28.000000000 -0400
++++ ./lisp/net/tramp.el	2016-08-21 09:48:00.190856327 -0400
+@@ -156,7 +156,7 @@
+ (defcustom tramp-encoding-shell
+   (if (memq system-type '(windows-nt))
+       (getenv "COMSPEC")
+-    "/bin/sh")
++    "@TERMUX_PREFIX@/bin/sh")
+   "Use this program for encoding and decoding commands on the local host.
+ This shell is used to execute the encoding and decoding command on the
+ local host, so if you want to use `~' in those commands, you should