Properly handle etc/local.properties memory settings

Build memory values (javac.maxmem and javadoc.maxmem) were
being overwritten by the defaults (600M) set in build.py.
Now, the values passed are just defaults which are only used
if nothing is set in local.properties or on the command-line.

Default also upped to 750MB since JDK5 and ice34 builds
are failing.

build.py

@@ -70,7 +70,7 @@ def find_java():
     return "java"
 
 def calculate_memory_args():
-    return "-Xmx600M -Djavac.maxmem=600M -Djavadoc.maxmem=600M -XX:MaxPermSize=256m".split(" ")
+    return "-Xmx600M -Djavac.maxmem.default=750M -Djavadoc.maxmem.default=750M -XX:MaxPermSize=256m".split(" ")
 
 def choose_omero_version():
     """

build.xml

@@ -912,4 +912,11 @@ omero.version=${omero.version}
 
     </target>
 
+    <target name="print-mem">
+        <echo>
+            javac.maxmem=${javac.maxmem}
+            javadoc.maxmem=${javadoc.maxmem}
+        </echo>
+    </target>
+
 </project>

components/antlib/resources/global.xml

@@ -227,6 +227,18 @@ with OMERO.
             </then>
         </if>
 
+        <!-- Now, if the memory settings have not been changed
+        check the defaults passed in on the command line -->
+        <if><and><not><isset property="javac.maxmem"/></not>
+            <isset property="javac.maxmem.default"/></and>
+            <then><property name="javac.maxmem" value="${javac.maxmem.default}"/></then>
+        </if>
+        <if><and><not><isset property="javadoc.maxmem"/></not>
+            <isset property="javadoc.maxmem.default"/></and>
+            <then><property name="javadoc.maxmem" value="${javadoc.maxmem.default}"/></then>
+        </if>
+
+
         <!-- Define properties :
                 The user's environment (env) overrides all other
                 variables, then comes the user defined