Working on KT-4574 Split If
Merge branch 'master' into split_if

Conflicts:
	generators/src/org/jetbrains/jet/generators/tests/GenerateTests.kt
	idea/tests/org/jetbrains/jet/plugin/intentions/AbstractCodeTransformationTest.java
	idea/tests/org/jetbrains/jet/plugin/intentions/CodeTransformationTestGenerated.java
KT-4574: New Intention: Split If