progress: use 'encoding.colwidth' to get column width of items correctly

Before this patch, 'progress' extension applies 'len' on byte sequence
to get column width of it, but it causes incorrect result, when length
of byte sequence and columns in display are different from each other
in multi-byte characters.

This patch uses 'encoding.colwidth' to get column width of items in
output line correctly, even if it contains multi-byte characters.

hgext/progress.py

@@ -142,7 +142,7 b' class progbar(object):'
                     add = encoding.trim(item, wid, leftside=True)
                 else:
                     add = encoding.trim(item, wid)
-                add += (wid - len(add)) * ' '
+                add += (wid - encoding.colwidth(add)) * ' '
             elif indicator == 'bar':
                 add = ''
                 needprogress = True

tests/test-progress.t

@@ -304,6 +304,7 b' from each other.'
   $ cat >> loop.py <<EOF
   > # use non-ascii characters as loop items of progress
   > loopitems = [
+  >     u'\u3042\u3044'.encode('utf-8'), # 2 x 2 = 4 columns
   >     u'\u3042\u3044\u3046'.encode('utf-8'), # 2 x 3 = 6 columns
   >     u'\u3042\u3044\u3046\u3048'.encode('utf-8'), # 2 x 4 = 8 columns
   > ]
@@ -317,8 +318,9 b' from each other.'
   > format = item+6
   > EOF
 
-  $ hg --encoding utf-8 -y loop --total 2 2
+  $ hg --encoding utf-8 -y loop --total 3 3
   \r (no-eol) (esc)
+  \xe3\x81\x82\xe3\x81\x84  \r (no-eol) (esc)
   \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\r (no-eol) (esc)
   \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\r (no-eol) (esc)
                        \r (no-eol) (esc)
@@ -329,8 +331,9 b' from each other.'
   > format = item-6
   > EOF
 
-  $ hg --encoding utf-8 -y loop --total 2 2
+  $ hg --encoding utf-8 -y loop --total 3 3
   \r (no-eol) (esc)
+  \xe3\x81\x82\xe3\x81\x84  \r (no-eol) (esc)
   \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\r (no-eol) (esc)
   \xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\r (no-eol) (esc)
                        \r (no-eol) (esc)