Multi-let #258
Only allow type declarations and value declarations in let bindings
Add test for closing over an outer variable in a let binding
Fix multiple let bindings in psci #258
Infix function declarations #311
Merge branch 'let'

Conflicts:
	src/Language/PureScript/Parser/Declarations.hs
Fix #315 and fix #316
Release notes
Parse signed numeric literals
Signed numeric literals test
Where clauses
Tests for where clauses
Include name of declaration in name-related error
Include decl name in errors for binding groups, data decls, type synonyms, etc
Ensure exported members don't rely on hidden types
Test for hidden type errors
Merge pull request #317 from garyb/negative-numbers

Negative number literals
Merge pull request #318 from garyb/where-clauses

Where clauses
Merge pull request #320 from garyb/hidden-type-error

Hidden type error
Merge pull request #319 from garyb/name-decl-errors

Name decl errors