fix test that was passing with the wrong error message
fix error message when fetching help for nested commands (fixes #1017)
split test scenario for help command (one for when wp is installed and other for when it is not)

see #1034
Merge pull request #1034 from rodrigoprimo/fix-help-error-msg

Fix error message when fetching help for nested commands
Add support for exporting specific tables
Dynamically build mysqldump command rather than repeating it
Add example for exporting specific tables
Merge pull request #1038 from CodeAwhile/db-export-tables

Add support for exporting specific tables
Whitelisted underscore in synopsis values.
Merge pull request #1039 from Rarst/synopsis-whitelist-underscore

Whitelisted underscore in synopsis values.
increase wordwrap width to 90

fixes display of long 'wp core config' example
Changed dump into export.
Merge pull request #1056 from clemens-tolboom/feature/dump-should-be-export

Changed dump into export.
show error when invalid format is passed
move --format=ids handling to individual commands
Merge pull request #1058 from wp-cli/format-ids

move --format=ids handling to individual commands
Add debugging info for current command.
Make arguments quoted.
--debug now prints command to STDOUT.
Remove quotes and extra tab.