Removes Val and Var productions
Removes AssignOp and New productions
Fixes infix expressions
Constraints ArgumentExprs
Prefer functions over assignments
Disallow opchar after assignment token
Fixes use of tokens in lexical grammar
Try to avoid Ascription expressions
Redefines opchars
Adds refinements
Refines expressions
Adds interesting test files
Introduces ArgumentExprsSeq

Needed to express layout constraints on ArgumentExprs lists
Updates float literal
Adds a few more test files
PostfixExpr may not be subexpression of itself
Refines pattern matching
Prefer prefix expressions over applications

Imagine the case !(a || b)
Prefer TmplDefBlockStat over DefBlockStat
Extends pattern matching test