Added Scala grammar

Added Scala grammar from http://www.scala-lang.org/files/archive/spec/2.11/13-syntax-summary.html
Update scala.g4
Added examples folder with instructions on building a working parser.
Added grammer rules to parse listener only entries.
Added grammar rules to correctly parse the BEQueath network protocol arguments.
Added a working (and valid) test tnsnames.ora file.
Removing Mutually Left-recursive Error
Update scala.g4
Merge pull request #1 from antlr/master

Update
Merge pull request #107 from vitorelli/master

NEW: Code ported to CSharp
Merge pull request #104 from NormanDunbar/master

Tnsnames grammar updated & completed.
Merge pull request #108 from lrlucena/master

Scala Grammar
Grouped operators with the same precedence so that these operators ar…
Merge pull request #109 from bkiers/ecmascript-operator-fix

Grouped operators with the same precedence so that these operators ar…
did not allow 1.01
Merge branch 'master' of github.com:antlr/grammars-v4
ABNF: add reference to RFC errata

Hex digits are case-insensitive according to the errata. It is apparently a common misunderstanding that the RFC only allows upper-case hex digits.
Merge pull request #112 from nathansgreen/patch-1

ABNF: add reference to RFC errata