- need to fix summary comment how to use the class;
- waitAppReady method should adjust timeout for timeout_factor;
- command line should be logged into System.out, not to System.err;
- getAppOutput method does not add functionality (as we have getOutput()) and is used by a single caller (test/jdk/sun/tools/jhsdb/heapconfig/TmtoolTestScenario.java). The conversion it does can be moved to the test.

Some issues with tests which use LingeredApp:
- test/hotspot/jtreg/serviceability/attach/AttachNegativePidTest.java
  starts LingeredApp but does not terminate it;
- test/jdk/sun/tools/jinfo/JInfoTest.java:
  uses 2 LingeredApps and cleans it by
            JInfoTestLingeredApp.stopApp(app1);
            JInfoTestLingeredApp.stopApp(app2);
  If 1st stopApp() throws an exception, 2nd app won't be terminated