[evince] unarr: Add instructions on how to update LZMA SDK

[Bastien Nocera <hadess src gnome org>]

commit b705652ca40ba10323c8c4a24d7c92a029a7627d
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Mar 14 14:02:17 2018 +0100

    unarr: Add instructions on how to update LZMA SDK
    
    https://bugzilla.gnome.org/show_bug.cgi?id=794327

 cut-n-paste/unarr/lzmasdk/README.lzmasdk |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)
---
diff --git a/cut-n-paste/unarr/lzmasdk/README.lzmasdk b/cut-n-paste/unarr/lzmasdk/README.lzmasdk
new file mode 100644
index 0000000..d605138
--- /dev/null
+++ b/cut-n-paste/unarr/lzmasdk/README.lzmasdk
@@ -0,0 +1,15 @@
+To update to the latest version of the LZMA SDK:
+1. Grab the latest version from:
+   https://sourceforge.net/projects/sevenzip/files/LZMA%20SDK/
+   and unpack it
+2. For the files in evince's copy/paste, copy the originals from the
+   C/ sub-directory of the SDK:
+   for i in *.[ch] ; do cp /tmp/lzma1803/C/$i . ; done
+3. Convert the copied files to Unix format:
+   dos2unix *.[ch]
+4. Use "git add -p" to apply only the sections that are of interest
+   and do not regress warning fixes (see commits a2aa919 and 5e1a0ef
+   for example)
+
+Note that you might end up with an empty commit (for example 79b5fe5)
+which is fine, as long as the change is documented.