VTTablet: Add tests for codex
Use goStyleVariableName
Check that the right errors are generated for bad listeners.
VTTablet: remove panics in codex

Remove panics from all functions in codex and return errors instead. To
keep this CL sane allow the callers to panic on error. Eventually we should remove
panics all the way up the stack.
Adding 'vtctl DeleteTablet' command.
Make VTGate protocol independent (WIP)
So we can avoid unnecessary conversion.
Docs: helicopter overview.
Use tablet_connection flag to determine data handler (WIP)
Merge branch 'vtocc'
Throttler must log skipped warnings after maxInterval

Currently the throttler warns of skipped messages only at the beginning
of next successful message. This could cause confusion for sudden spikes followed by
long quiet periods. Fix here is to log skipped warning at the end of
maxInterval.
parser: Drop obsolete tokens TABLE_EXPR, etc.
parser: prep work for boolean expressions.
parser: []byte->string for some non-terminals.
parser: boolean_expression -> BoolExpr
parser: drop obsolete tokens
Merge branch 'parser'
parser: Improve grammar on tuple handling
Move datahandle files to tabletconn
Move tests to tabletconn
Make tablet_conn interface protocol independent