GROOVY-6933: Add swap() to List and array.
Collections.swap() returns nothing, but this method returns this object.
First bits of work around quality builds:
   * re-enabled checkstyle
   * generate HTML report
   * CodeNarc, Cobertura disabled
Upgrade to Asciidoctor Gradle plugin 0.7.3
Merge pull request #481 from yukoba/Swap

GROOVY-6933: Add swap() to List and array
merge the two font css imports into one for only one download from the remote font server
Enable CodeNarc in quality check
Added Jacoco coverage
Fixed "indy" system property leaking into Gradle build script itself
GROOVY-6915: VerifyError in markup template engine if "equals" is used instead of a semicolon
Test case for GROOVY-6939
Test case for GROOVY-6940
Test case for GROOVY-6941
Fixes GROOVY-6941
   * VerifyError using property notation on dynamic model variable inside a block
   * corresponds to a static compiler mixed mode bug
   * added 'templateengine.compile.debug' property to debug generated bytecode
Merge pull request #1 from groovy/master

Added the documentation for Program structure. Added the test cases for the same.