[INTERNAL] Create a task of type CMake

[jguidoux]

For the moment. If the user want to activate the cmake build in Gradle it should do that :

task launchCMake(type: Exec, group: "init") {

    workingDir "$buildDir"
    executable "cmake"
    args  ".."
}
compileCpp.dependsOn launchCMake

It will be interesting to create a task of type CMake wich simplify the configuration. This task extends the Exec task. So the user can just write this :

task launchCMake(type: CMake, group: "init")
compileCpp.dependsOn launchCMake

Of course, the user can override all defaults configurations :

task launchCMake(type: CMake, group: "init") {

    workingDir "foo
    executable "/usr/local/bin/cmake-3.1/"
    args  "../myProjects"
}
compileCpp.dependsOn launchCMake