Run "./gradlew idea" to have a fresh IntelliJ IDEA project file generated. Do not use the default GPars_IDEAX project file,
since you are likely to run into problems with unresolved dependencies on third-party libraries,
as the default project file is primarily targeted to be used for code analysis on the Continuous Integration server (TeamCity).

Find complete developer guidelines at http://gpars.codehaus.org/Developer+Zone
