move sort from method to function
remove abstract properties

Don't seem to be necessary
whitespace
add expr predicates
isinstance(..., TableExpr) -> istabular in compute
clean up mongo TableExpr -> istabular migration
isinstance(..., TableExpr) -> istabular in api
isinstance(TableExpr) -> istabular in server
remove TableExpr from blaze/foo.py
remove isinstance(..., TableExpr) in much of expr/
rename .columns to .names internally
use .names instead of .columns
Like is an Expr, has no iscolumn
move Like to expr/strings.py
move datetime to expr/datetime.py
lower imports from expr.table to expr
projection retains child shape
table_repr -> expr_repr
associated tests for table_repr -> expr_repr
move dir and getattr from TableExpr to Expr