Add parser. FLex&Bison required.
REPL added. GNU readline required.
Add gitignore for vim swap file; Add makefile for branch test and adjust include relative path; Convert all input into uppercase."
Enhanced repl. Use global var and emit() function to process stmts.
Fix parser shifit/reduce conflict. Add more complete support for stmt parse. Add repl reaction for emitted statements.
Use Queue to store un-processed stmts. Add lowercase keyword support for
SQL syntax.