Upgrade to Gradle 1.0-rc1

- Fix deprecation warnings about dynamic properties; favor use of
   "extra properties extensions" per [1]

 - Certain such deprecations are still issued due to violations within
   the docbook-reference plugin. These will be fixed in an upcoming
   revision of the plugin, at which point spring-framework will upgrade
   to depend on it and these warnings will be eliminated

[1] http://gradle.org/docs/current/dsl/org.gradle.api.plugins.ExtraPropertiesExtension.html

Issue: SPR-9327

build.gradle

@@ -17,7 +17,7 @@ configure(allprojects) {
     sourceCompatibility=1.5
     targetCompatibility=1.5
 
-    slf4jLog4jVersion = '1.5.10'
+    ext.slf4jLog4jVersion = '1.5.10'
 
     [compileJava, compileTestJava]*.options*.compilerArgs = ['-Xlint:none']
 
@@ -85,7 +85,7 @@ configure(subprojects) { subproject ->
 
 project("spring-asm") {
     description = 'Spring ASM'
-    asmVersion = '2.2.3'
+    ext.asmVersion = '2.2.3'
 
     configurations {
         asm
@@ -542,7 +542,7 @@ configure(rootProject) {
         description = "Builds -${classifier} archive, containing all jars and docs, " +
                       "suitable for community download page."
 
-        baseDir = "${project.name}-${project.version}";
+        def baseDir = "${project.name}-${project.version}";
 
         from('src/dist') {
             include 'readme.txt'
@@ -581,7 +581,7 @@ configure(rootProject) {
 
     task wrapper(type: Wrapper) {
         description = 'Generates gradlew[.bat] scripts'
-        gradleVersion = '1.0-milestone-8a'
+        gradleVersion = '1.0-rc-1'
     }
 }