[MCOMPILER-179] Warnings displayed as errors

Tested with local test projects.
[maven-release-plugin] prepare release plexus-compiler-1.9.2
[maven-release-plugin] prepare for next development iteration
upgrade compiler plugin for faster build
updated parent pom
Fix related to MCOMPILER-160 where unparseable errors are missed in case of warning messages.

Signed-off-by: Anders Hammar <anders@hammar.net>
Test and fix for http://jira.codehaus.org/browse/PLXCOMP-206
Test and fix for http://jira.codehaus.org/browse/PLXCOMP-206
Tweak test to run only on Windows
Same fix as in 282dfdda86 but for forked compilation.

Signed-off-by: Anders Hammar <anders@hammar.net>
Merge pull request #8 from andham/MCOMPILER-160

Same fix as in 282dfdda86 but for forked compilation.
Thanks!
rewrite a bit pull 6 for support PLXCOMP-1
with still supporting 1.5.
javax.tools is detected with loading the class or not.
reuse the created JavaCompiler to be more performant!
Note nothing say it's thread safe so potential issues with multi threaded env.
implements reuseStrategy mechanism as for javac compiler
better naming convention for static final fields
Merge pull request #9 from olamy/PLXCOMP-1

Rewrite pull 6 for support of PLXCOMP1
bump version to 2.0-SNAPSHOT
explain use of fqcn
added descriptions
Refactor to have a bean as compiler result rather than a List of messages.
Ensure 2.x changes are backwards compatible.

These changes make the 2.x branch compatible with maven-compiler-plugin 2.x.  maven-compiler-plugin 3.x must make changes to AbstractCompilerMojo to call both variants of the compile method.  Eg, something like this:

		CompilerResult compilerResult;
        try
        {
            try 
            {
               compilerResult = compiler.performCompile( compilerConfiguration );
            } 
            catch (CompilerNotImplementedException cnie) 
            {
                messages = compiler.compile( compilerConfiguration );
				compilerResult = makeCompilerResult(messages);
            }
        }
        catch ( Exception e )
        {
            // TODO: don't catch Exception
            throw new MojoExecutionException( "Fatal error compiling", e );
        }

I renamed the new compile method to performCompile, but I am not too happy with the name. Perhaps you can find a better one.