JS backend: add kotlin_lib_ecma_common.js
JS backend: add MergeEcmaTest
JS backend: move Object. function from ecma3 to ecma_common & add templates for createTrait, class, e.t.c.
JS backend: add several MergeEcma Tests
JS backend: mute ECMA.v3 tests
JS backend: add debug info in Delegate Property Test
JS backend: migrate to kotlin_lib_ecma_common