Fix problem with spaces in JAVACMD or CLASSPATH for windows batch scripts

[opax]

This should resolve issue #114 .
In addition to the quoted JAVACMD, CLASSPATH is also quoted so that spaces in the classpath do not crash the batch script.
The test expectations have been updated accordingly.

[aikebah]

@opax On a quick read I think that your patch will break in case of an unset JAVACMD env variable the case of

appassembler/appassembler-maven-plugin/src/main/java/org/codehaus/mojo/appassembler/daemon/script/DefaultScriptGenerator.java

Line 206 in 99cc4e5

context.put( "JAVA_BINARY", "start /min javaw" );

As JAVACMD, if unset, is set to JAVA_BINARY in the template. If you then later quote JAVACMD it will look for a binary called "start /min javaw" instead of a binary "start" with arguments "/min" and "javaw"