accept '=>' anywhere '->' is acccepcted
add tests for es6-style arrow function literal
do not require single parameter of arrow function should be closed with parentheses
add tests for arrow functions
add arrow function-like type notation
add tests for arrow-function-like type notation
Revert "add tests for arrow-function-like type notation"

This reverts commit ccca4793c933eaab454df6237a33a671831ef049.
Revert "add arrow function-like type notation"

This reverts commit 89277a784e34311f5f306689adb9c2ba8730ffd7.
update completion test
add a failing test regarding #247
Merge branch 'refactor-generator'
Merge pull request #288 from jsx/wasabiz/feature/es6-arrow-function

es6 arrow function
[refactor] introduce StringLiteralExpression#getDecoded() for returning the decoded string, instead of letting the outside world decode the literal
add failing test (found during refactor)
[bugfix] ```empty_multiline_string_constant as boolean``` was misoptimized to true (fixes the failing test added in prev. commit)
add failing tests (found during refactor)
add failing test
[refactor] introduce #getDecoded() for all of the primitive literals, and fix bugs registered in the prev. commit
amend the reasoning and the limitation of detecting conflicting case-labels
Merge branch 'kazuho/experiments/primitive-getdecoded' into kazuho/experiments/macroic-file-and-line