[pitivi] docs/HACKING: Explain the proper use of multiline strings

[Jean-FranÃois Fortin Tam <jfft src gnome org>]

commit b323bb6468aa9d69f07717bd503a50744166a12e
Author: Jean-FranÃois Fortin Tam <nekohayo gmail com>
Date:   Thu Aug 30 23:45:49 2012 -0700

    docs/HACKING: Explain the proper use of multiline strings

 docs/HACKING |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/docs/HACKING b/docs/HACKING
index d80d47d..5534415 100644
--- a/docs/HACKING
+++ b/docs/HACKING
@@ -24,6 +24,15 @@ Hacking on PiTiVi
       and what you think makes the most easily readable code.
 
 
+  For translatable multiline strings, use Python's implicit line continuation
+  instead of manually concatenating with the plus (+) sign. For example, this
+  is incorrect, gettext will consider it as two separate strings:
+        _("<b>First line</b>\n" +
+          "Some second line that is too long to fit on the first line anyway"
+
+  Instead, this is the translator-friendly version:
+        _("<b>First line</b>\n"
+          "Some second line that is too long to fit on the first line anyway"
 
 - for method names we use the mixedCase style
   Ex :