define OpenBSD property

Index: build.xml
--- build.xml.orig
+++ build.xml
@@ -98,6 +98,9 @@
         <condition property="dist.os" value="os400">
             <equals arg1="${os.name}" arg2="OS/400"/>
         </condition>
+        <condition property="dist.os" value="openbsd">
+            <equals arg1="${os.name}" arg2="OpenBSD"/>
+        </condition>
         <property name="dist.os" value="${os.name}"/>
         
         <!-- Resolve an architecture to use in release names. -->
@@ -427,6 +430,7 @@
         <condition property="make.name" value="gmake">
             <or>
                 <isset property="is.freebsd"/>
+                <isset property="is.openbsd"/>
                 <isset property="is.solaris"/>
             </or>
         </condition>
@@ -444,6 +448,7 @@
             <or>
                 <isset property="is.linux"/>
                 <isset property="is.freebsd"/>
+                <isset property="is.openbsd"/>
                 <isset property="is.solaris"/>
             </or>
         </condition>
@@ -1846,6 +1851,10 @@ wrapper.filter.action.999=NONE]]></replacevalue>
         <release-delta-extract-platform osname="linux"   osarch="armel"     bits="32" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
         <release-delta-extract-platform osname="linux"   osarch="armhf"     bits="32" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
         <release-delta-extract-platform osname="linux"   osarch="arm"       bits="64" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
+        <release-delta-extract-platform osname="openbsd"   osarch="x86"     bits="32" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
+        <release-delta-extract-platform osname="openbsd"   osarch="x86"     bits="64" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
+        <release-delta-extract-platform osname="openbsd"   osarch="arm"     bits="64" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
+        <release-delta-extract-platform osname="openbsd"   osarch="sparc"   bits="64" wrapperbinhead="wrapper" wrapperbintail=""     wrapperlibhead="libwrapper" wrapperlibtail=".so"     archivetype="tar.gz"/>
     </target>
     <target name="release-delta" depends="pre-release:check, release-delta:init, release-delta:extract-platforms">
         <property name="deltareleasefile" value="wrapper-delta-pack-${version}"/>