Update build files
 - Update build to Gradle 2.0 (be mindful of += with collections)
 - Apply bintray and coveralls plugins
 - Setup aggregate cobertura reports
 - Switch back to jcenter() in repositories as build is now Gradle 2.0 compatible
 - Update cobertura classpath with jfxrt jar
test: nodeHasLabel() does not perform instance check for Text #123
Apply source/target compatibility to all subprojects; Shutdown pedantic doclint in JDK8+
fix(ToolkitAppLauncher): AppLauncher could not retrieve primary Stage on OSX.
Merge pull request #126 from hastebrot/fix-app-launcher-osx

fix(ToolkitAppLauncher): AppLauncher could not retrieve primary Stage on OSX.
Merge pull request #122 from aalmiray/update_gradle_build

Update build files
chore(gradle): Temporarily remove BinTray support to fix Gradle view refresh in IntelliJ IDEA.
Merge pull request #127 from hastebrot/master

chore(gradle): Temporarily remove BinTray support to fix Gradle view ref...
chore(gradle): reintroduce BinTray support.
Merge pull request #128 from hastebrot/master

chore(gradle): reintroduce BinTray support.
Merge pull request #124 from naimdjon/master

test: nodeHasLabel() does not perform instance check for Text #123