Fixing build string.

Version number turning up more than once. Looking at the situation
I could only see the former mechanism as trouble. I deleted
build.number and in ant am generating the build string only from
tools/get-scala-revision. We may need to revisit when the time comes to
build a release.

Author: paulp

README.rst

@@ -14,7 +14,6 @@ part of the repository but are either automatically generated by the
 build script or user-created if needed.  This is not a complete listing. :: 
   scala/
    +--build/                    Build products output directory for ant.
-   +--build.number              The version number of the current distribution.
    +--build.xml                 The main Ant build script.
    +--dist/                     The destination folder for Scala distributions.
    +--docs/                     Documentation and sample code.

build.number

@@ -251,18 +251,13 @@ INITIALISATION
       <os family="windows"/>
     </condition>
 
-    <exec osfamily="unix" executable="tools/get-scala-revision" outputproperty="git.describe" failifexecutionfails="false" />
-    <exec osfamily="windows" executable="tools/get-scala-revision.bat" outputproperty="git.describe" failifexecutionfails="false" />
+    <!-- Generating version string -->
+    <exec osfamily="unix" executable="tools/get-scala-revision" outputproperty="version.number" failifexecutionfails="false" />
+    <exec osfamily="windows" executable="tools/get-scala-revision.bat" outputproperty="version.number" failifexecutionfails="false" />
     <!-- some default in case something went wrong getting the revision -->
-    <property name="git.describe" value="-unknown-"/>
+    <property name="version.number" value="-unknown-"/>
     <property name="init.avail" value="yes"/>
 
-    <!-- Generating version number -->
-    <property file="${basedir}/build.number"/>
-    <property
-      name="version.number"
-      value="${version.major}.${version.minor}.${version.patch}.${git.describe}"/>
-
     <!-- And print-out what we are building -->
     <echo message="       build time: ${time.human}" />
     <echo message="     java version: ${java.vm.name} ${java.version}" />