#KT-1623 fixed

Added test for case when type from overridden method has same short name as something already present.

 #KT-1602 fixed

 #KT-1602 fixed

Changed completion for classes, so if they have the same name as already imported, new import is not added. Qualified name is inserted instead.

Conflicts:
	build-tools/core/src/org/jetbrains/jet/buildtools/core/BytecodeCompiler.java
	compiler/cli/src/org/jetbrains/jet/cli/jvm/K2JVMCompiler.java
	compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/CompileEnvironmentConfiguration.java
	compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/JetCoreEnvironment.java
	compiler/tests/org/jetbrains/jet/JetTestUtils.java
	compiler/tests/org/jetbrains/jet/codegen/CompileTextTest.java

Got rid of returning empty range list in position strategies (in places where they depend on syntax errors).

Got rid of returning empty range list in position strategies (in places where they don't depend on syntax errors).

(not just to library root)

This reverts commit 90910cae.

This reverts commit 95f9bcba.

we should definitely make asserts unconditional

* drop dependency on stdlib/alt-headers in the most tests
* assign to myEnvironment at most once in JetLiteFixture
* more tests do not compile runtime

(not just to library root)