1.7.6: Quick binding with `::`, ANTLR syntax style for LLLPG

Please visit the following links regarding

• Changes to EC# and LeMP
• Changes to LLLPG
• Changes to Loyc Core libraries

The main new features are

• #useSequenceExpressions;, which is used near the top of an EC# file to enable the quick-bind operator :: and in-situ declaration of out and ref variables as in int.TryParse(s, out int x)
• LLLPG now supports an ANTLR-style input mode in which grammars can look very similar to ANTLR grammars (see here for more information)