New Intention Action: Replace with operator assign

Replaces a statement of the form a = a + b with a statement of the form
a += b.
New Intention Action: Replace with traditional assign.

This takes an expression of the form a += b and converts it to an
expression form a = a + b.
Merge pull request #386 from pk382/operator-assign-intention

Intention: Convert between "+=" and "a = a + b"
#KT-4563 Fixed
Reuse intention test data in inspection tests
Updated to IDEA 135.667 (13.1.2 EAP)
KT-4794: Added functionality to KT-4574: Split If. Intention is now offered inside IF keyword
Merge pull request #431 from gavinkeusch/split_if_new

KT-4794: Added functionality to KT-4574: Split If. Intention is now offered inside IF keyword
Refactoring of CompileTimeConstant, introduce flag to represent a constant being referenced by a variable
Intention to simplify boolean expressions that have expressions in them that can be simplified to constants
Merge pull request #392 from wutalman/simplify_booleans

KT-4569: Intention to simplify boolean expressions with constants #KT-4569 Fixed
Intention for adding explicit type arguments at function calls
Intention for removing explicit type arguments at function calls