Bug 23757 - Add mode="delete" to <edit>

Add two edit mode, "delete" and "delete_all".
what values are being deleted depends on <test> as documented.
if the target object is same to what is tested, matching value there
will be deleted. otherwise all of values in the object will be deleted.
so this would means both edit mode will not take any expressions.

e.g.

Given that the testing is always true here, the following rules:

  <match>
    <test name="foo" compare="eq">
      <string>bar</string>
    </test>
    <edit name="foo" mode="delete"/>
  </match>

will removes "bar" string from "foo" object. and:

  <match>
    <test name="foo" compare="eq">
      <string>foo</string>
    </test>
    <edit name="bar" mode="delete"/>
  </match>

will removes all of values in "bar" object.

1 files changed, 2 insertions, 0 deletions

diff --git a/doc/fontconfig-user.sgml b/doc/fontconfig-user.sgml
index 90e246b6..eeff69ad 100644
--- a/doc/fontconfig-user.sgml
+++ b/doc/fontconfig-user.sgml
@@ -425,6 +425,8 @@ with "same" binding using the value from the matched pattern element.
   "prepend_first"         Insert at head of list  Insert at head of list
   "append"                Append after matching   Append at end of list
   "append_last"           Append at end of list   Append at end of list
+  "delete"                Delete matching value   Delete all values
+  "delete_all"            Delete all values       Delete all values
     </programlisting>
   </para></refsect2>
   <refsect2><title><literal>&lt;int&gt;</literal>, <literal>&lt;double&gt;</literal>, <literal>&lt;string&gt;</literal>, <literal>&lt;bool&gt;</literal></title><para>