Some README tweaks, a forkArg param to ease visualvm connections for …

…sampling.

README.md

@@ -18,6 +18,14 @@ Thank you for your interest in c3p0. I do hope that you find it useful!
 
 ### Building c3p0
 
+For now (v0.10.0), c3p0 is built under a Java 11 VM, targetting JDK 7 classfiles for continued compatibility with legacy apps.
+In order to remind me to switch to Java 11, the build will fail with an Exception if it detects an unexpected version.
+You can comment this requirement out of `build.sc` if you like. It's the line that looks like
+
+```scala
+  require( sys.props("java.runtime.version").startsWith("11"), s"Bad build JVM: ${sys.props("java.runtime.version")} -- We currently expect to build under Java 11. (We generate Java $JvmCompatVersion compatible source files.)" )
+```
+
 c3p0 relies on the excellent build tool [`mill`](https://mill-build.com/).
 
 Install `mill`. Then, within this repository direcory, run
@@ -34,8 +42,6 @@ If you maintain a local ivy repository, You can customize `publishVersion` in [`
 $ mill publishLocal
 ```
 
-For now (v0.10.x), c3p0 is built under a Java 11 VM, targetting JDK 7 classfiles for continued compatibility with legacy apps.
-
 To build the documentation
 
 ```plaintext

build.sc

@@ -274,6 +274,7 @@ object c3p0 extends RootModule with JavaModule with PublishModule {
       //"-Xrunhprof:file=/tmp/java.hprof,doe=y,format=b" ::
       //"-verbose:class"
       //"-ea" ::
+      "-Djava.rmi.server.hostname=localhost" ::
       s"""-Djava.util.logging.config.file=${millSourcePath / "conf-logging" / "logging.properties"}""" ::
       Nil
     }