rml2pdf: use ustr() instead of unicode()

When strings are 8-bit utf8-encoded, unicode will break with the usual:
  UnicodeDecodeError: 'ascii' codec can't decode byte 0xce in position ..
message. ustr() will have better luck in those cases.

Conflicts:

	bin/report/render/rml2pdf/utils.py

bzr revid: p_christ@hol.gr-20101123151930-8r9q9gg7r902i2nv

bin/report/render/rml2pdf/utils.py

@@ -45,6 +45,7 @@ import reportlab
 
 import tools
 from tools.safe_eval import safe_eval as eval
+from tools import ustr
 
 _regex = re.compile('\[\[(.+?)\]\]')
 
@@ -131,11 +132,11 @@ def _process_text(self, txt):
                 if isinstance(txt, basestring):
                     result += str2xml(txt)
                 elif (txt is not None) and (txt is not False):
-                    result += unicode(txt)
+                    result += ustr(txt)
         return result
 
 def text_get(node):
-    return ''.join([unicode(n.text) for n in node])
+    return ''.join([ustr(n.text) for n in node])
 
 units = [
     (re.compile('^(-?[0-9\.]+)\s*in$'), reportlab.lib.units.inch),