Initial work on INTO
Saving progress towards being able to select ignored columns.
Merge branch 'master' into into

Conflicts:
	bayesdb/engine.py
	bayesdb/parser.py
Merge branch 'master' into ignore

Conflicts:
	bayesdb/client.py
	bayesdb/parser.py
remove hist, add plot/summarize
Merge branch 'pyparsing' of https://github.com/mit-probabilistic-computing-project/BayesDB into pyparsing
bql_statement top level
bql_statement top level
bug fixes in tests and grammar
Added parser for LABEL COLUMNS
Added engine function to label columns
added given clause
fixed bugs to make grammar compatible with existing test, also docs
Add column labels to persistence layer
Loop to insert or overwrite each label submitted by user
Only label columns if they actually exist in btable, otherwise raise error
Column labels now saved in persistence layer
Added parser for SHOW LABELS
Added engine function to return column labels
Pretty-print table for SHOW LABELS